Grade VII – Acids, Bases, and Salts MCQs

Table of Contents

Grade VII – Acids, Bases, and Salts

Multiple Choice Questions

Q1: Do all edible substances have the same taste?

A) Yes B) No

Answer: B) No

Q2: What substances are suggested for the treasure hunt activity?

A) Lemon, curd, soap solution, tamarind, toothpaste, common salt, vinegar, and baking soda paste. B) Lemon, sugar, soap solution, salt, vinegar, and water. C) Lemon, curd, vinegar, water, toothpaste, common salt, and baking soda paste. D) Lemon, curd, soap solution, water, toothpaste, common salt, and vinegar.

Answer: A) Lemon, curd, soap solution, tamarind, toothpaste, common salt, vinegar, and baking soda paste.

Q3: What will one person in the pair do during the activity?

A) Ask the other person to taste and identify substances. B) Prepare the substances for tasting. C) Blindfold the other person. D) Taste the substances themselves.

Answer: A) Ask the other person to taste and identify substances.

Q4: What are participants supposed to note in their observations?

A) The color of the substances. B) The taste of the substances. C) Whether the substances are slippery or rough to touch. D) The smell of the substances.

Answer: C) Whether the substances are slippery or rough to touch.

Q5: Is it advisable to taste unknown substances to determine their nature?

A) Yes B) No

Answer: B) No

Q6: Why do substances like lemon juice and vinegar taste sour?

A) They contain bases, which are sour in taste. B) They contain acids, which are sour in taste. C) They contain salts, which are sour in taste. D) They contain water, which is sour in taste.

Answer: B) They contain acids, which are sour in taste.

Q7: What does the Latin word ‘acer’ mean?

A) Bitter B) Sweet C) Sour D) Salty

Answer: C) Sour

Q8: List three properties of acids.

A) Sour in taste, soluble in water, and turn blue litmus paper red. B) Bitter in taste, insoluble in water, and turn red litmus paper blue. C) Sweet in taste, soluble in water, and turn blue litmus paper red. D) Sour in taste, insoluble in water, and turn red litmus paper blue.

Answer: A) Sour in taste, soluble in water, and turn blue litmus paper red.

Q9: Why are acids stored in glass containers instead of metal containers?

A) Because acids are corrosive and can destroy paper, cloth, and metal. B) Because glass is more durable than metal. C) Because metal containers are too expensive. D) Because acids react with glass to form a protective layer.

Answer: A) Because acids are corrosive and can destroy paper, cloth, and metal.

Q10: What precautions should you take when diluting a strong acid?

A) Add water to acid slowly and while stirring. B) Add acid to water slowly and while stirring. C) Add water to acid quickly without stirring. D) Add acid to water quickly without stirring.

Answer: B) Add acid to water slowly and while stirring.

Q11: What is a common reaction involving acids?

A) Acids react with metals to form hydrogen gas and salts. B) Acids react with bases to form carbon dioxide. C) Acids react with water to form oxygen gas. D) Acids react with salts to form bases.

Answer: A) Acids react with metals to form hydrogen gas and salts.

Q12: What is the purpose of a pH scale?

A) To measure the temperature of a substance. B) To measure how acidic or basic a substance is. C) To measure the density of a substance. D) To measure the weight of a substance.

Answer: B) To measure how acidic or basic a substance is.

Q13: What pH value range indicates that a substance is acidic?

A) Greater than 7 B) Equal to 7 C) Less than 7 D) Exactly 7

Answer: C) Less than 7

Q14: What are the two types of acids mentioned?

A) Organic acids and mineral acids. B) Strong acids and weak acids. C) Natural acids and synthetic acids. D) Solid acids and liquid acids.

Answer: A) Organic acids and mineral acids.

Q15: List some properties of organic acids.

A) They are found naturally, are weak acids, and contain carbon and hydrogen atoms. B) They are human-made, are strong acids, and contain hydrogen atoms. C) They are found naturally, are strong acids, and contain carbon atoms. D) They are human-made, are weak acids, and contain carbon and hydrogen atoms.

Answer: A) They are found naturally, are weak acids, and contain carbon and hydrogen atoms.

Q16: What is the natural source of citric acid?

A) Vinegar B) Soap solution C) Citrus fruits such as oranges and lemons D) Baking soda

Answer: C) Citrus fruits such as oranges and lemons

Q17: How is lactic acid different from sulphuric acid?

A) Lactic acid is an organic acid found naturally in foods like curd and is a weak acid, while sulphuric acid is a strong mineral acid used in industry. B) Lactic acid is a strong mineral acid used in industry, while sulphuric acid is an organic acid found naturally in foods like curd and is a weak acid. C) Lactic acid is a weak mineral acid found in foods like curd, while sulphuric acid is a strong organic acid used in industry. D) Lactic acid and sulphuric acid have no differences.

Answer: A) Lactic acid is an organic acid found naturally in foods like curd and is a weak acid, while sulphuric acid is a strong mineral acid used in industry.

Q18: Name a natural source of ascorbic acid.

A) Lemon B) Vinegar C) Amla D) Soap solution

Answer: C) Amla

Q19: What are mineral acids?

A) Acids found naturally in fruits. B) Acids prepared from mineral resources of the earth. C) Acids found in animals. D) Acids found in vegetables.

Answer: B) Acids prepared from mineral resources of the earth.

Q20: List some characteristics of mineral acids.

A) They are weak acids, human-made, and contain carbon atoms. B) They are strong acids, human-made, and contain hydrogen but no carbon atoms. C) They are weak acids, found naturally, and contain hydrogen atoms. D) They are strong acids, found naturally, and contain carbon atoms.

Answer: B) They are strong acids, human-made, and contain hydrogen but no carbon atoms.

Q21: Why must mineral acids be handled carefully?

A) They can cause severe burns to the skin and should not be handled with bare hands. B) They can cause allergies. C) They can cause stains on clothes. D) They can be used as cleaning agents.

Answer: A) They can cause severe burns to the skin and should not be handled with bare hands.

Q22: Name three common mineral acids.

A) Citric acid, lactic acid, and acetic acid. B) Sulphuric acid (H₂SO₄), nitric acid (HNO₃), and hydrochloric acid (HCl). C) Formic acid, citric acid, and malic acid. D) Oxalic acid, citric acid, and tartaric acid.

Answer: B) Sulphuric acid (H₂SO₄), nitric acid (HNO₃), and hydrochloric acid (HCl).

Q23: What is the difference between dilute and concentrated acids?

A) Dilute acids have a large quantity of water and a small amount of acid, while concentrated acids have a small quantity of water and a large amount of acid. B) Dilute acids have a small quantity of water and a large amount of acid, while concentrated acids have a large quantity of water and a small amount of acid. C) Dilute acids are weak acids, while concentrated acids are strong acids. D) Dilute acids are found naturally, while concentrated acids are human-made.

Answer: A) Dilute acids have a large quantity of water and a small amount of acid, while concentrated acids have a small quantity of water and a large amount of acid.

Q24: Why should acids never be tasted to identify them?

A) They are dangerous and can cause harm; other methods should be used for identification. B) They are too sour in taste. C) They are too bitter in taste. D) They are too salty in taste.

Answer: A) They are dangerous and can cause harm; other methods should be used for identification.

Q25: What is a common use of ascorbic acid (Vitamin C)?

A) It is important for a healthy body. B) It is used as a cleaning agent. C) It is used in car batteries. D) It is used in fertilizer production.

Answer: A) It is important for a healthy body.

Q26: Why is hydrochloric acid added to food?

A) It helps in the digestion of food. B) It enhances the flavor of food. C) It preserves the food. D) It cleans the food.

Answer: A) It helps in the digestion of food.

Q27: What is the role of acetic acid in food?

A) It is used as a food preservative. B) It enhances the color of food. C) It helps in the digestion of food. D) It cleans the food.

Answer: A) It is used as a food preservative.

Q28: List some uses of sulphuric acid.

A) It is used in car and inverter batteries, fertilizer production, and manufacturing of dyes, detergents, and synthetic fibers like rayon. B) It is used in food preservation and flavor enhancement. C) It is used in household cleaning agents and textiles. D) It is used in medicine and cosmetics.

Answer: A) It is used in car and inverter batteries, fertilizer production, and manufacturing of dyes, detergents, and synthetic fibers like rayon.

Q29: What is a primary use of nitric acid?

A) It is used in the manufacture of fertilizers and synthetic dyes. B) It is used in food preservation. C) It is used in household cleaning agents. D) It is used in medicine.

Answer: A) It is used in the manufacture of fertilizers and synthetic dyes.

Q30: For what purpose is acetic acid used besides food preservation?

A) It enhances the flavor of food, is used in ink for textile printing, and in the manufacture of pharmaceuticals, rubber, and plastics. B) It cleans the food. C) It is used in car batteries. D) It is used in fertilizer production.

Answer: A) It enhances the flavor of food, is used in ink for textile printing, and in the manufacture of pharmaceuticals, rubber, and plastics.

Q31: What is hydrochloric acid used for in industries?

A) It is used for removing rust from iron and steel, and in the production of various cleaning compounds. B) It is used in food preservation. C) It is used in medicine. D) It is used in cosmetics.

Answer: A) It is used for removing rust from iron and steel, and in the production of various cleaning compounds.

Q32: What are some common properties of bases?

A) Bases have a bitter taste, are slippery to touch, turn red litmus paper blue, and have a pH of more than 7 on the pH scale. B) Bases have a sour taste, are rough to touch, turn blue litmus paper red, and have a pH of less than 7 on the pH scale. C) Bases have a sweet taste, are slippery to touch, turn red litmus paper blue, and have a pH of exactly 7 on the pH scale. D) Bases have a salty taste, are rough to touch, turn blue litmus paper red, and have a pH of more than 7 on the pH scale.

Answer: A) Bases have a bitter taste, are slippery to touch, turn red litmus paper blue, and have a pH of more than 7 on the pH scale.

Q33: List some strong bases mentioned in the text.

A) Citric acid and acetic acid. B) Sodium hydroxide and potassium hydroxide. C) Sulphuric acid and nitric acid. D) Hydrochloric acid and formic acid.

Answer: B) Sodium hydroxide and potassium hydroxide.

Q34: What are some uses of calcium hydroxide?

A) Neutralizing acidic soil in agriculture, as a chief ingredient in whitewash, and treating wastewater from factories. B) Enhancing the flavor of food, used in ink for textile printing. C) Removing rust from iron and steel, and in the production of various cleaning compounds. D) Used in car and inverter batteries, fertilizer production, and manufacturing of dyes, detergents, and synthetic fibers like rayon.

Answer: A) Neutralizing acidic soil in agriculture, as a chief ingredient in whitewash, and treating wastewater from factories.

Q35: What is sodium hydroxide used for?

A) Unclogging drains, manufacturing paper, soaps, textiles, and detergents. B) Enhancing the flavor of food, used in ink for textile printing. C) Removing rust from iron and steel, and in the production of various cleaning compounds. D) Used in car and inverter batteries, fertilizer production, and manufacturing of dyes, detergents, and synthetic fibers like rayon.

Answer: A) Unclogging drains, manufacturing paper, soaps, textiles, and detergents.

Q36: What is potassium hydroxide commonly used in?

A) Production of disinfectants, liquid soaps, shampoo, and drain cleaners. B) Enhancing the flavor of food, used in ink for textile printing. C) Removing rust from iron and steel, and in the production of various cleaning compounds. D) Used in car and inverter batteries, fertilizer production, and manufacturing of dyes, detergents, and synthetic fibers like rayon.

Answer: A) Production of disinfectants, liquid soaps, shampoo, and drain cleaners.

Q37: How is magnesium hydroxide used medicinally?

A) As an antacid to neutralize stomach acidity. B) Enhancing the flavor of food, used in ink for textile printing. C) Removing rust from iron and steel, and in the production of various cleaning compounds. D) Used in car and inverter batteries, fertilizer production, and manufacturing of dyes, detergents, and synthetic fibers like rayon.

Answer: A) As an antacid to neutralize stomach acidity.

Q38: What is the use of ammonium hydroxide?

A) In the manufacture of household cleaners and other chemicals. B) Enhancing the flavor of food, used in ink for textile printing. C) Removing rust from iron and steel, and in the production of various cleaning compounds. D) Used in car and inverter batteries, fertilizer production, and manufacturing of dyes, detergents, and synthetic fibers like rayon.

Answer: A) In the manufacture of household cleaners and other chemicals.

Q39: What is aqua regia, and what does it dissolve?

A) Aqua regia is made up of three parts of concentrated hydrochloric acid (HCl) and one part of concentrated nitric acid (HNO₃). It is capable of dissolving gold. B) Aqua regia is made up of two parts of concentrated hydrochloric acid (HCl) and one part of concentrated nitric acid (HNO₃). It is capable of dissolving silver. C) Aqua regia is made up of three parts of concentrated hydrochloric acid (HCl) and two parts of concentrated nitric acid (HNO₃). It is capable of dissolving platinum. D) Aqua regia is made up of two parts of concentrated hydrochloric acid (HCl) and one part of concentrated nitric acid (HNO₃). It is capable of dissolving copper.

Answer: A) Aqua regia is made up of three parts of concentrated hydrochloric acid (HCl) and one part of concentrated nitric acid (HNO₃). It is capable of dissolving gold.

Q40: Which of the following substances are acidic in nature?

A) Soap solution and baking soda B) Curd and amla C) Toothpaste and common salt D) Lemon and soap solution

Answer: B) Curd and amla

Q41: You are performing an experiment barehanded and suddenly your palm feels slippery and slimy. What one of the following are you feeling in your hand?

A) Sodium hydroxide, a base B) Hydrochloric acid, an acid C) Vinegar, an acid D) Lemon juice, an acid

Answer: A) Sodium hydroxide, a base

Q42: What are P and Q in the chart related to acids?

A) P–Organic acid, Q–Mineral acid B) P–Mineral acid, Q–Organic acid C) P–Weak acid, Q–Strong acid D) P–Strong acid, Q–Weak acid

Answer: B) P–Mineral acid, Q–Organic acid

Q43: What are indicators?

A) Substances that show different colors in acidic and basic solutions to test whether a substance is acidic or basic. B) Substances that change color in neutral solutions only. C) Substances that change the taste of acidic and basic solutions. D) Substances that react with water to form acids and bases.

Answer: A) Substances that show different colors in acidic and basic solutions to test whether a substance is acidic or basic.

Q44: Name some natural indicators.

A) Turmeric, litmus, and red cabbage juice B) Phenolphthalein, methyl orange, and bromothymol blue C) Vinegar, baking soda, and lemon juice D) Soap solution, toothpaste, and common salt

Answer: A) Turmeric, litmus, and red cabbage juice

Q45: What does litmus solution do in an acidic solution?

A) It turns blue when added to an acidic solution. B) It turns red when added to an acidic solution. C) It turns green when added to an acidic solution. D) It remains colorless when added to an acidic solution.

Answer: B) It turns red when added to an acidic solution.

Q46: What change occurs when litmus solution is added to a basic solution?

A) It turns red when added to a basic solution. B) It turns blue when added to a basic solution. C) It turns green when added to a basic solution. D) It remains colorless when added to a basic solution.

Answer: B) It turns blue when added to a basic solution.

Q47: Why does neutral litmus solution not change color in a neutral solution?

A) Because it only reacts to the presence of acid or base; in a neutral solution, it remains its original mauve (purple) color. B) Because it reacts to the presence of neutral substances only. C) Because it reacts with water to form a new color. D) Because it turns red in acidic and blue in basic solutions.

Answer: A) Because it only reacts to the presence of acid or base; in a neutral solution, it remains its original mauve (purple) color.

Q48: What is the use of litmus paper in testing substances?

A) Litmus paper is used to identify acidic or basic nature of substances. Blue litmus turns red under acidic conditions and red litmus turns blue under basic conditions. B) Litmus paper is used to measure the temperature of substances. C) Litmus paper is used to change the taste of substances. D) Litmus paper is used to change the color of substances.

Answer: A) Litmus paper is used to identify acidic or basic nature of substances. Blue litmus turns red under acidic conditions and red litmus turns blue under basic conditions.

Q49: What are some safety precautions to follow while handling chemicals in a laboratory?

A) Wear a safety apron and gloves, always conduct experiments under the supervision of a teacher, read the instructions before the experiment, and keep the mouth of the test tube away from you while heating. B) Taste the chemicals to identify them. C) Handle the chemicals with bare hands. D) Mix all the chemicals together to observe the reaction.

Answer: A) Wear a safety apron and gloves, always conduct experiments under the supervision of a teacher, read the instructions before the experiment, and keep the mouth of the test tube away from you while heating.

Q50: How do you determine the nature of solutions using litmus paper?

A) By observing the color change in litmus paper when a solution is applied to it. Acidic solutions turn blue litmus paper red, and basic solutions turn red litmus paper blue. B) By measuring the temperature of the solutions. C) By tasting the solutions to identify their nature. D) By smelling the solutions to identify their nature.

Answer: A) By observing the color change in litmus paper when a solution is applied to it. Acidic solutions turn blue litmus paper red, and basic solutions turn red litmus paper blue.

Q51: What is the effect of lemon juice on litmus paper?

A) Lemon juice has no effect on red litmus paper but turns blue litmus paper red, indicating it is an acidic solution. B) Lemon juice has no effect on blue litmus paper but turns red litmus paper blue, indicating it is a basic solution. C) Lemon juice has no effect on either blue or red litmus paper, indicating it is a neutral solution. D) Lemon juice turns both blue and red litmus paper yellow, indicating it is a neutral solution.

Answer: A) Lemon juice has no effect on red litmus paper but turns blue litmus paper red, indicating it is an acidic solution.

Q52: What are the expected outcomes for detergent and baking soda solutions on litmus paper?

A) Detergent solution should change red litmus paper to blue (basic) and have no change on blue litmus paper. Baking soda solution should also behave similarly as it is basic. B) Detergent solution should change blue litmus paper to red (acidic) and have no change on red litmus paper. Baking soda solution should also behave similarly as it is acidic. C) Detergent solution should have no change on both blue and red litmus paper, indicating it is neutral. Baking soda solution should also behave similarly as it is neutral. D) Detergent solution should change both blue and red litmus paper to yellow, indicating it is neutral. Baking soda solution should also behave similarly as it is neutral.

Answer: A) Detergent solution should change red litmus paper to blue (basic) and have no change on blue litmus paper. Baking soda solution should also behave similarly as it is basic.

Q53: How should you handle the observation and conclusion part of the litmus paper activity?

A) Students are expected to fill in the table with their observations about the effect of the test solutions on red and blue litmus paper and conclude whether the solutions are acidic, basic, or neutral based on the color change. B) Students should taste the solutions to identify their nature. C) Students should smell the solutions to identify their nature. D) Students should measure the temperature of the solutions to identify their nature.

Answer: A) Students are expected to fill in the table with their observations about the effect of the test solutions on red and blue litmus paper and conclude whether the solutions are acidic, basic, or neutral based on the color change.

Q54: What is turmeric used for as an indicator?

A) Turmeric is used as a natural indicator to identify basic solutions. B) Turmeric is used as a natural indicator to identify acidic solutions. C) Turmeric is used as a natural indicator to identify neutral solutions. D) Turmeric is used as a natural indicator to identify both acidic and basic solutions.

Answer: A) Turmeric is used as a natural indicator to identify basic solutions.

Q55: How do you prepare turmeric paper for use as an indicator?

A) Make a paste by adding a little amount of water to turmeric powder, spread this paste on blotting paper (filter paper), and let it dry. B) Make a solution by adding turmeric powder to vinegar, dip blotting paper in the solution, and let it dry. C) Make a solution by adding turmeric powder to lemon juice, dip blotting paper in the solution, and let it dry. D) Make a paste by adding a little amount of water to turmeric powder, spread this paste on blotting paper (filter paper), and use it immediately.

Answer: A) Make a paste by adding a little amount of water to turmeric powder, spread this paste on blotting paper (filter paper), and let it dry.

Q56: What happens when turmeric paper comes into contact with a basic solution?

A) The yellow turmeric paper turns red when exposed to a basic solution. B) The yellow turmeric paper turns blue when exposed to a basic solution. C) The yellow turmeric paper turns green when exposed to a basic solution. D) The yellow turmeric paper remains yellow when exposed to a basic solution.

Answer: A) The yellow turmeric paper turns red when exposed to a basic solution.

Q57: Why does turmeric paper not change color when exposed to acidic solutions?

A) Turmeric paper has no effect and remains yellow when exposed to acidic solutions. B) Turmeric paper turns red when exposed to acidic solutions. C) Turmeric paper turns blue when exposed to acidic solutions. D) Turmeric paper turns green when exposed to acidic solutions.

Answer: A) Turmeric paper has no effect and remains yellow when exposed to acidic solutions.

Q58: How can turmeric be used in an activity to decode messages?

A) By writing a message with a soap solution (which is basic), and using turmeric paper to reveal the message as the paper will turn red where the soap has been applied. B) By writing a message with lemon juice (which is acidic), and using turmeric paper to reveal the message as the paper will turn yellow where the lemon juice has been applied. C) By writing a message with water, and using turmeric paper to reveal the message as the paper will turn green where the water has been applied. D) By writing a message with vinegar (which is acidic), and using turmeric paper to reveal the message as the paper will turn blue where the vinegar has been applied.

Answer: A) By writing a message with a soap solution (which is basic), and using turmeric paper to reveal the message as the paper will turn red where the soap has been applied.

Q59: What is the purpose of using turmeric paper in the activity described?

A) To determine whether given solutions are basic, acidic, or neutral. B) To measure the temperature of the solutions. C) To change the taste of the solutions. D) To change the color of the solutions.

Answer: A) To determine whether given solutions are basic, acidic, or neutral.

Q60: What effect does soap solution have on turmeric paper?

A) The soap solution turns the yellow turmeric paper red, indicating it is a basic solution. B) The soap solution turns the yellow turmeric paper blue, indicating it is an acidic solution. C) The soap solution turns the yellow turmeric paper green, indicating it is a neutral solution. D) The soap solution has no effect on the yellow turmeric paper, indicating it is a neutral solution.

Answer: A) The soap solution turns the yellow turmeric paper red, indicating it is a basic solution.

Q61: What inference can be made if turmeric paper shows no change in color when tested with a solution?

A) The solution could be either acidic or neutral, as they do not change the color of turmeric paper. B) The solution could be basic, as they do not change the color of turmeric paper. C) The solution could be neutral, as they change the color of turmeric paper to yellow. D) The solution could be neutral, as they change the color of turmeric paper to red.

Answer: A) The solution could be either acidic or neutral, as they do not change the color of turmeric paper.

Q62: How do you perform the test with turmeric paper?

A) Place a drop of the solution to be tested on a strip of turmeric paper and observe any color change. B) Taste the solution to identify its nature. C) Smell the solution to identify its nature. D) Measure the temperature of the solution to identify its nature.

Answer: A) Place a drop of the solution to be tested on a strip of turmeric paper and observe any color change.

Q63: Predict the expected outcome when turmeric paper is tested with dilute hydrochloric acid and dilute nitric acid.

A) There should be no change in color, indicating that both are either acidic or neutral. B) The turmeric paper should turn red, indicating that both are basic. C) The turmeric paper should turn blue, indicating that both are neutral. D) The turmeric paper should turn green, indicating that both are neutral.

Answer: A) There should be no change in color, indicating that both are either acidic or neutral.

Q64: What should be observed when testing a detergent solution with turmeric paper?

A) Similar to the soap solution, the detergent solution should turn the turmeric paper red if it is basic. B) The detergent solution should turn the turmeric paper blue if it is acidic. C) The detergent solution should turn the turmeric paper green if it is neutral. D) The detergent solution should have no effect on the turmeric paper if it is neutral.

Answer: A) Similar to the soap solution, the detergent solution should turn the turmeric paper red if it is basic.

Q65: What is China rose solution used for?

A) It is used as a natural indicator to determine if solutions are acidic or basic. B) It is used as a natural indicator to determine if solutions are neutral. C) It is used as a natural indicator to change the taste of solutions. D) It is used as a natural indicator to change the color of solutions.

Answer: A) It is used as a natural indicator to determine if solutions are acidic or basic.

Q66: How do you prepare China rose indicator?

A) Collect some petals of China rose flower, add them to warm water until the water turns light pink, then filter to obtain the China rose indicator. B) Collect some leaves of China rose plant, add them to warm water until the water turns light green, then filter to obtain the China rose indicator. C) Collect some petals of China rose flower, add them to cold water until the water turns light pink, then filter to obtain the China rose indicator. D) Collect some leaves of China rose plant, add them to cold water until the water turns light green, then filter to obtain the China rose indicator.

Answer: A) Collect some petals of China rose flower, add them to warm water until the water turns light pink, then filter to obtain the China rose indicator.

Q67: What color does China rose solution turn when added to an acidic solution?

A) It turns green when added to an acidic solution. B) It turns yellow when added to an acidic solution. C) It turns blue when added to an acidic solution. D) It turns magenta (dark pink) when added to an acidic solution.

Answer: D) It turns magenta (dark pink) when added to an acidic solution.

Q68: What happens when China rose solution is added to a basic solution?

A) It turns blue when added to a basic solution. B) It turns green when added to a basic solution. C) It turns yellow when added to a basic solution. D) It turns red when added to a basic solution.

Answer: B) It turns green when added to a basic solution.

Q69: Does China rose solution change color in neutral solutions?

A) Yes, China rose solution turns yellow in neutral solutions. B) Yes, China rose solution turns blue in neutral solutions. C) No, China rose solution has no effect on neutral substances. D) No, China rose solution turns green in neutral substances.

Answer: C) No, China rose solution has no effect on neutral substances.

Q70: What is phenolphthalein and how does it indicate pH?

A) Phenolphthalein is a synthetic indicator that turns pink in basic solutions and remains colorless in acidic and neutral solutions. B) Phenolphthalein is a natural indicator that turns red in basic solutions and remains colorless in acidic and neutral solutions. C) Phenolphthalein is a synthetic indicator that turns green in acidic solutions and remains colorless in basic and neutral solutions. D) Phenolphthalein is a natural indicator that turns blue in neutral solutions and remains colorless in acidic and basic solutions.

Answer: A) Phenolphthalein is a synthetic indicator that turns pink in basic solutions and remains colorless in acidic and neutral solutions.

Q71: How could you demonstrate the effect of three indicators on dilute hydrochloric acid, nitric acid, and sulphuric acid?

A) By noting the color changes of litmus paper, turmeric paper, and China rose solution when each is added to the acids and then recording the observations in a table format. B) By measuring the temperature changes when each indicator is added to the acids. C) By tasting the solutions when each indicator is added to the acids. D) By smelling the solutions when each indicator is added to the acids.

Answer: A) By noting the color changes of litmus paper, turmeric paper, and China rose solution when each is added to the acids and then recording the observations in a table format.

Q72: What taste is associated with acids and bases?

A) Acids are bitter, while bases are sour. B) Acids are sweet, while bases are salty. C) Acids are sour, while bases are bitter. D) Acids are salty, while bases are sweet.

Answer: C) Acids are sour, while bases are bitter.

Q73: What is the effect of acids and bases on turmeric paper?

A) Acids have no effect on yellow turmeric paper, whereas bases turn it red. B) Acids turn yellow turmeric paper red, whereas bases have no effect. C) Acids turn yellow turmeric paper blue, whereas bases have no effect. D) Acids turn yellow turmeric paper green, whereas bases have no effect.

Answer: A) Acids have no effect on yellow turmeric paper, whereas bases turn it red.

Q74: How do acids and bases react with phenolphthalein?

A) Acids cause no color change in phenolphthalein (remains colorless), while bases turn phenolphthalein pink. B) Acids turn phenolphthalein blue, while bases cause no color change (remains colorless). C) Acids turn phenolphthalein green, while bases cause no color change (remains colorless). D) Acids turn phenolphthalein red, while bases cause no color change (remains colorless).

Answer: A) Acids cause no color change in phenolphthalein (remains colorless), while bases turn phenolphthalein pink.

Q75: What color changes occur with China rose solution when added to acids and bases?

A) Acids turn China rose indicator magenta, while bases turn it green. B) Acids turn China rose indicator yellow, while bases turn it red. C) Acids turn China rose indicator blue, while bases turn it green. D) Acids turn China rose indicator green, while bases turn it magenta.

Answer: A) Acids turn China rose indicator magenta, while bases turn it green.

Q76: How do methyl orange and other indicators react to acids and bases?

A) Methyl orange turns red in acidic solutions and yellow in basic solutions. B) Methyl orange turns yellow in acidic solutions and red in basic solutions. C) Methyl orange turns blue in acidic solutions and yellow in basic solutions. D) Methyl orange turns green in acidic solutions and red in basic solutions.

Answer: A) Methyl orange turns red in acidic solutions and yellow in basic solutions.

Q77: What are the effects of acids and bases on solubility in water?

A) Most acids are soluble in water, while most bases are insoluble in water. B) Most acids are insoluble in water, while most bases are soluble in water. C) Both acids and bases are equally soluble in water. D) Both acids and bases are equally insoluble in water.

Answer: A) Most acids are soluble in water, while most bases are insoluble in water.

Q78: What is a neutralization reaction?

A) A reaction where an acid and a base react to form salt and water, often releasing heat. B) A reaction where a base reacts with water to form an acid. C) A reaction where two acids react to form a salt. D) A reaction where an acid reacts with water to form a base.

Answer: A) A reaction where an acid and a base react to form salt and water, often releasing heat.

Q79: What is the typical outcome of mixing hydrochloric acid and sodium hydroxide?

A) The reaction produces sodium chloride (salt), water, and heat. B) The reaction produces carbon dioxide, water, and heat. C) The reaction produces oxygen gas, water, and heat. D) The reaction produces hydrogen gas, water, and heat.

Answer: A) The reaction produces sodium chloride (salt), water, and heat.

Q80: How does phenolphthalein behave in a neutralization reaction?

A) Phenolphthalein turns pink in a basic solution. During neutralization, as the solution approaches neutral pH, the pink color disappears. B) Phenolphthalein turns blue in a basic solution. During neutralization, as the solution approaches neutral pH, the blue color disappears. C) Phenolphthalein turns green in a basic solution. During neutralization, as the solution approaches neutral pH, the green color disappears. D) Phenolphthalein turns red in a basic solution. During neutralization, as the solution approaches neutral pH, the red color disappears.

Answer: A) Phenolphthalein turns pink in a basic solution. During neutralization, as the solution approaches neutral pH, the pink color disappears.

Q81: What are the steps to perform a neutralization reaction experiment using phenolphthalein?

A) Start with a basic solution of sodium hydroxide and add phenolphthalein to turn it pink. Gradually add hydrochloric acid, stirring continuously, until the pink color disappears, indicating neutrality. B) Start with an acidic solution of hydrochloric acid and add phenolphthalein to turn it blue. Gradually add sodium hydroxide, stirring continuously, until the blue color disappears, indicating neutrality. C) Start with a basic solution of sodium hydroxide and add phenolphthalein to turn it green. Gradually add hydrochloric acid, stirring continuously, until the green color disappears, indicating neutrality. D) Start with an acidic solution of hydrochloric acid and add phenolphthalein to turn it red. Gradually add sodium hydroxide, stirring continuously, until the red color disappears, indicating neutrality.

Answer: A) Start with a basic solution of sodium hydroxide and add phenolphthalein to turn it pink. Gradually add hydrochloric acid, stirring continuously, until the pink color disappears, indicating neutrality.

Q82: What does the disappearance of the pink color in the phenolphthalein indicate?

A) It indicates that the acid has neutralized the base, reaching a neutral pH where phenolphthalein is colorless. B) It indicates that the base has neutralized the acid, reaching a neutral pH where phenolphthalein is colorless. C) It indicates that the solution has become acidic. D) It indicates that the solution has become basic.

Answer: A) It indicates that the acid has neutralized the base, reaching a neutral pH where phenolphthalein is colorless.

Q83: What would you observe if you added a drop of sodium hydroxide to the neutralized solution?

A) Adding a drop of sodium hydroxide would turn the solution pink again, indicating the solution has become basic. B) Adding a drop of sodium hydroxide would turn the solution blue again, indicating the solution has become basic. C) Adding a drop of sodium hydroxide would turn the solution green again, indicating the solution has become basic. D) Adding a drop of sodium hydroxide would turn the solution red again, indicating the solution has become basic.

Answer: A) Adding a drop of sodium hydroxide would turn the solution pink again, indicating the solution has become basic.

Q84: Why is it important to stir the solution continuously during the experiment?

A) Continuous stirring helps mix the reactants thoroughly and ensures the indicator (phenolphthalein) accurately shows the pH change throughout the solution. B) Continuous stirring helps cool down the solution. C) Continuous stirring helps heat up the solution. D) Continuous stirring helps change the color of the solution.

Answer: A) Continuous stirring helps mix the reactants thoroughly and ensures the indicator (phenolphthalein) accurately shows the pH change throughout the solution.

Q85: What is a salt in chemical terms?

A) Salt is a compound formed by the neutralization of an acid and a base, such as copper sulfate or ferrous sulfate. B) Salt is a compound formed by the reaction of two acids. C) Salt is a compound formed by the reaction of two bases. D) Salt is a compound formed by the reaction of water and an acid.

Answer: A) Salt is a compound formed by the neutralization of an acid and a base, such as copper sulfate or ferrous sulfate.

Q86: What are some common properties of salts?

A) Salts exist in solid state, can be acidic, basic, or neutral in nature, have high melting and boiling points, and most are soluble in water. Salt solutions are generally good conductors of electricity. B) Salts exist in liquid state, can be acidic, basic, or neutral in nature, have low melting and boiling points, and most are insoluble in water. Salt solutions are generally poor conductors of electricity. C) Salts exist in solid state, can be acidic, basic, or neutral in nature, have low melting and boiling points, and most are insoluble in water. Salt solutions are generally poor conductors of electricity. D) Salts exist in liquid state, can be acidic, basic, or neutral in nature, have high melting and boiling points, and most are soluble in water. Salt solutions are generally good conductors of electricity.

Answer: A) Salts exist in solid state, can be acidic, basic, or neutral in nature, have high melting and boiling points, and most are soluble in water. Salt solutions are generally good conductors of electricity.

Q87: List some common salts and their everyday uses.

A) Sodium chloride as table salt, sodium carbonate as washing soda, and sodium bicarbonate as baking soda. B) Sodium hydroxide as lye, potassium hydroxide as potash, and calcium hydroxide as lime. C) Hydrochloric acid as muriatic acid, nitric acid as aqua fortis, and sulphuric acid as oil of vitriol. D) Citric acid as sour salt, tartaric acid as cream of tartar, and acetic acid as vinegar.

Answer: A) Sodium chloride as table salt, sodium carbonate as washing soda, and sodium bicarbonate as baking soda.

Q88: What are the steps to prepare a salt like copper sulfate in a laboratory?

A) Start with dilute sulfuric acid, add copper oxide powder until it no longer dissolves (indicating excess), filter the mixture to remove the excess copper oxide, and then evaporate the filtrate to obtain copper sulfate crystals. B) Start with dilute nitric acid, add copper oxide powder until it no longer dissolves (indicating excess), filter the mixture to remove the excess copper oxide, and then evaporate the filtrate to obtain copper nitrate crystals. C) Start with dilute hydrochloric acid, add copper oxide powder until it no longer dissolves (indicating excess), filter the mixture to remove the excess copper oxide, and then evaporate the filtrate to obtain copper chloride crystals. D) Start with dilute sulfuric acid, add zinc oxide powder until it no longer dissolves (indicating excess), filter the mixture to remove the excess zinc oxide, and then evaporate the filtrate to obtain zinc sulfate crystals.

Answer: A) Start with dilute sulfuric acid, add copper oxide powder until it no longer dissolves (indicating excess), filter the mixture to remove the excess copper oxide, and then evaporate the filtrate to obtain copper sulfate crystals.

Q89: What does the evaporation process achieve in the preparation of copper sulfate crystals?

A) Evaporation removes the water, leaving behind the salt crystals. B) Evaporation adds water, creating a more concentrated solution. C) Evaporation neutralizes the acid in the solution. D) Evaporation removes impurities from the solution.

Answer: A) Evaporation removes the water, leaving behind the salt crystals.

Q90: Why is the excess copper oxide filtered out during the preparation of copper sulfate?

A) To ensure that only the dissolved salt is left in the solution, which can then be crystallized. B) To ensure that the acid remains in the solution. C) To ensure that the water remains in the solution. D) To ensure that the impurities are added to the solution.

Answer: A) To ensure that only the dissolved salt is left in the solution, which can then be crystallized.

Q91: What is the appearance of copper sulfate crystals?

A) Copper sulfate crystals are blue and have a crystalline structure. B) Copper sulfate crystals are white and have a crystalline structure. C) Copper sulfate crystals are green and have a crystalline structure. D) Copper sulfate crystals are red and have a crystalline structure.

Answer: A) Copper sulfate crystals are blue and have a crystalline structure.

Q92: What safety precautions should be taken when preparing copper sulfate in the laboratory?

A) Wear safety goggles, gloves, and a lab coat to protect against splashes of acid and hot solutions. Handle all chemicals with care and follow the teacher’s instructions. B) Taste the chemicals to ensure their purity. C) Mix all the chemicals together quickly to observe the reaction. D) Smell the chemicals to identify their nature.

Answer: A) Wear safety goggles, gloves, and a lab coat to protect against splashes of acid and hot solutions. Handle all chemicals with care and follow the teacher’s instructions.

Q93: What does the reaction between an acid and a metal oxide produce?

A) It produces salt and water, along with a release of heat. B) It produces salt and hydrogen gas. C) It produces salt and carbon dioxide gas. D) It produces salt and oxygen gas.

Answer: A) It produces salt and water, along with a release of heat.

Q94: What is the general form of the reaction between an acid and a metal oxide?

A) Acid + Metal oxide → Salt + Water B) Acid + Metal oxide → Salt + Hydrogen gas C) Acid + Metal oxide → Salt + Carbon dioxide gas D) Acid + Metal oxide → Salt + Oxygen gas

Answer: A) Acid + Metal oxide → Salt + Water

Q95: How would you demonstrate the reaction of hydrochloric acid with copper oxide in the laboratory?

A) Add copper oxide to dilute hydrochloric acid until no more dissolves, filter the mixture to remove excess copper oxide, and evaporate the filtrate to obtain copper chloride crystals. B) Add copper oxide to dilute sulfuric acid until no more dissolves, filter the mixture to remove excess copper oxide, and evaporate the filtrate to obtain copper sulfate crystals. C) Add copper oxide to dilute nitric acid until no more dissolves, filter the mixture to remove excess copper oxide, and evaporate the filtrate to obtain copper nitrate crystals. D) Add zinc oxide to dilute hydrochloric acid until no more dissolves, filter the mixture to remove excess zinc oxide, and evaporate the filtrate to obtain zinc chloride crystals.

Answer: A) Add copper oxide to dilute hydrochloric acid until no more dissolves, filter the mixture to remove excess copper oxide, and evaporate the filtrate to obtain copper chloride crystals.

Q96: What does the reaction between an acid and a metal carbonate or metal bicarbonate produce?

A) It produces salt, water, and carbon dioxide gas. B) It produces salt, water, and hydrogen gas. C) It produces salt, water, and oxygen gas. D) It produces salt, water, and chlorine gas.

Answer: A) It produces salt, water, and carbon dioxide gas.

Q97: What is the general form of the reaction between an acid and a metal carbonate?

A) Acid + Metal carbonate → Salt + Water + Carbon dioxide B) Acid + Metal carbonate → Salt + Water + Hydrogen gas C) Acid + Metal carbonate → Salt + Water + Oxygen gas D) Acid + Metal carbonate → Salt + Water + Chlorine gas

Answer: A) Acid + Metal carbonate → Salt + Water + Carbon dioxide

Q98: How would you demonstrate the reaction of hydrochloric acid with sodium bicarbonate in the laboratory?

A) Add sodium bicarbonate to dilute hydrochloric acid, observe the effervescence due to carbon dioxide gas formation, and then test the gas by passing it through limewater to see if it turns milky. B) Add sodium bicarbonate to dilute sulfuric acid, observe the effervescence due to carbon dioxide gas formation, and then test the gas by passing it through limewater to see if it turns milky. C) Add sodium bicarbonate to dilute nitric acid, observe the effervescence due to carbon dioxide gas formation, and then test the gas by passing it through limewater to see if it turns milky. D) Add zinc carbonate to dilute hydrochloric acid, observe the effervescence due to carbon dioxide gas formation, and then test the gas by passing it through limewater to see if it turns milky.

Answer: A) Add sodium bicarbonate to dilute hydrochloric acid, observe the effervescence due to carbon dioxide gas formation, and then test the gas by passing it through limewater to see if it turns milky.

Q99: What does the reaction between an acid and a metal produce?

A) It produces salt and hydrogen gas. B) It produces salt and water. C) It produces salt and carbon dioxide gas. D) It produces salt and oxygen gas.

Answer: A) It produces salt and hydrogen gas.

Q100: What is the general form of the reaction between an acid and a metal?

A) Acid + Metal → Salt + Hydrogen gas B) Acid + Metal → Salt + Water C) Acid + Metal → Salt + Carbon dioxide gas D) Acid + Metal → Salt + Oxygen gas

Answer: A) Acid + Metal → Salt + Hydrogen gas

Q101: How would you demonstrate the reaction of hydrochloric acid with magnesium in the laboratory?

A) Add a strip of magnesium to dilute hydrochloric acid and observe the bubbles of hydrogen gas. Test the gas by bringing a burning matchstick near the mouth of the test tube; the gas burns with a ‘pop’ sound. B) Add a strip of magnesium to dilute sulfuric acid and observe the bubbles of hydrogen gas. Test the gas by bringing a burning matchstick near the mouth of the test tube; the gas burns with a ‘pop’ sound. C) Add a strip of magnesium to dilute nitric acid and observe the bubbles of hydrogen gas. Test the gas by bringing a burning matchstick near the mouth of the test tube; the gas burns with a ‘pop’ sound. D) Add a strip of zinc to dilute hydrochloric acid and observe the bubbles of hydrogen gas. Test the gas by bringing a burning matchstick near the mouth of the test tube; the gas burns with a ‘pop’ sound.

Answer: A) Add a strip of magnesium to dilute hydrochloric acid and observe the bubbles of hydrogen gas. Test the gas by bringing a burning matchstick near the mouth of the test tube; the gas burns with a ‘pop’ sound.

Q102: What does the reaction between a base and a metal produce?

A) It produces salt and hydrogen gas. B) It produces salt and water. C) It produces salt and carbon dioxide gas. D) It produces salt and oxygen gas.

Answer: A) It produces salt and hydrogen gas.

Q103: What is the general form of the reaction between a base and a metal?

A) Base + Metal → Salt + Hydrogen gas B) Base + Metal → Salt + Water C) Base + Metal → Salt + Carbon dioxide gas D) Base + Metal → Salt + Oxygen gas

Answer: A) Base + Metal → Salt + Hydrogen gas

Q104: How would you demonstrate the reaction of sodium hydroxide with aluminum in the laboratory?

A) Add a piece of aluminum foil to dilute sodium hydroxide and observe the bubbles of hydrogen gas. Test the gas by bringing a burning matchstick near the mouth of the test tube; the gas burns with a ‘pop’ sound. B) Add a piece of aluminum foil to dilute hydrochloric acid and observe the bubbles of hydrogen gas. Test the gas by bringing a burning matchstick near the mouth of the test tube; the gas burns with a ‘pop’ sound. C) Add a piece of aluminum foil to dilute sulfuric acid and observe the bubbles of hydrogen gas. Test the gas by bringing a burning matchstick near the mouth of the test tube; the gas burns with a ‘pop’ sound. D) Add a piece of aluminum foil to dilute nitric acid and observe the bubbles of hydrogen gas. Test the gas by bringing a burning matchstick near the mouth of the test tube; the gas burns with a ‘pop’ sound.

Answer: A) Add a piece of aluminum foil to dilute sodium hydroxide and observe the bubbles of hydrogen gas. Test the gas by bringing a burning matchstick near the mouth of the test tube; the gas burns with a ‘pop’ sound.

Q105: What is a precipitation reaction?

A) A reaction where two soluble salts react to form an insoluble salt and a soluble salt. B) A reaction where two soluble salts react to form two soluble salts. C) A reaction where two insoluble salts react to form two soluble salts. D) A reaction where two insoluble salts react to form an insoluble salt and a soluble salt.

Answer: A) A reaction where two soluble salts react to form an insoluble salt and a soluble salt.

Q106: How would you demonstrate a precipitation reaction using lead nitrate and potassium iodide solutions?

A) Mix lead nitrate solution with potassium iodide solution. The reaction produces a yellow precipitate of lead iodide, which is insoluble in water. B) Mix lead nitrate solution with sodium chloride solution. The reaction produces a white precipitate of lead chloride, which is insoluble in water. C) Mix lead nitrate solution with silver nitrate solution. The reaction produces a grey precipitate of lead nitrate, which is insoluble in water. D) Mix lead nitrate solution with sodium hydroxide solution. The reaction produces a brown precipitate of lead hydroxide, which is insoluble in water.

Answer: A) Mix lead nitrate solution with potassium iodide solution. The reaction produces a yellow precipitate of lead iodide, which is insoluble in water.

Q107: What is the general form of a precipitation reaction?

A) Soluble salt 1 + Soluble salt 2 → Insoluble salt (precipitate) + Soluble salt 3 B) Soluble salt 1 + Soluble salt 2 → Soluble salt 3 + Soluble salt 4 C) Insoluble salt 1 + Insoluble salt 2 → Soluble salt 3 + Soluble salt 4 D) Insoluble salt 1 + Insoluble salt 2 → Insoluble salt (precipitate) + Soluble salt 3

Answer: A) Soluble salt 1 + Soluble salt 2 → Insoluble salt (precipitate) + Soluble salt 3

Q108: What is the appearance of lead iodide precipitate formed in the precipitation reaction?

A) Lead iodide precipitate is yellow and insoluble in water. B) Lead iodide precipitate is white and insoluble in water. C) Lead iodide precipitate is grey and insoluble in water. D) Lead iodide precipitate is brown and insoluble in water.

Answer: A) Lead iodide precipitate is yellow and insoluble in water.

Q109: How can the nature of salts be determined using litmus paper?

A) Prepare aqueous solutions of salts and test with red and blue litmus papers. Acidic salts turn blue litmus paper red, basic salts turn red litmus paper blue, and neutral salts show no effect on either. B) Prepare aqueous solutions of salts and test with red litmus paper only. Acidic salts turn red litmus paper blue, basic salts turn red litmus paper green, and neutral salts show no effect. C) Prepare aqueous solutions of salts and test with blue litmus paper only. Acidic salts turn blue litmus paper red, basic salts turn blue litmus paper green, and neutral salts show no effect. D) Prepare aqueous solutions of salts and test with both red and blue litmus papers. Acidic salts turn both litmus papers green, basic salts turn both litmus papers yellow, and neutral salts show no effect.

Answer: A) Prepare aqueous solutions of salts and test with red and blue litmus papers. Acidic salts turn blue litmus paper red, basic salts turn red litmus paper blue, and neutral salts show no effect on either.

Q110: How would you describe the pH scale and its significance?

A) The pH scale ranges from 0 to 14, with 7 being neutral. Values below 7 indicate acidity, and values above 7 indicate basicity. The pH scale is significant for determining the strength of acidic or basic solutions. B) The pH scale ranges from 0 to 14, with 7 being neutral. Values below 7 indicate basicity, and values above 7 indicate acidity. The pH scale is significant for determining the strength of acidic or basic solutions. C) The pH scale ranges from 0 to 10, with 5 being neutral. Values below 5 indicate acidity, and values above 5 indicate basicity. The pH scale is significant for determining the strength of acidic or basic solutions. D) The pH scale ranges from 0 to 10, with 5 being neutral. Values below 5 indicate basicity, and values above 5 indicate acidity. The pH scale is significant for determining the strength of acidic or basic solutions.

Answer: A) The pH scale ranges from 0 to 14, with 7 being neutral. Values below 7 indicate acidity, and values above 7 indicate basicity. The pH scale is significant for determining the strength of acidic or basic solutions.

Q111: What is the typical pH range for strong acids and strong bases?

A) Strong acids have a pH of 0 to 3, and strong bases have a pH of 11 to 14. B) Strong acids have a pH of 4 to 6, and strong bases have a pH of 8 to 10. C) Strong acids have a pH of 7 to 10, and strong bases have a pH of 0 to 3. D) Strong acids have a pH of 0 to 6, and strong bases have a pH of 8 to 14.

Answer: A) Strong acids have a pH of 0 to 3, and strong bases have a pH of 11 to 14.

Q112: What is the typical pH range for weak acids and weak bases?

A) Weak acids have a pH of 4 to 6, and weak bases have a pH of 8 to 10. B) Weak acids have a pH of 0 to 3, and weak bases have a pH of 11 to 14. C) Weak acids have a pH of 7 to 10, and weak bases have a pH of 0 to 3. D) Weak acids have a pH of 0 to 6, and weak bases have a pH of 8 to 14.

Answer: A) Weak acids have a pH of 4 to 6, and weak bases have a pH of 8 to 10.

Q113: How can the pH of a solution be determined?

A) The pH of a solution can be determined using pH paper, universal indicator, or pH meter, each showing a color change corresponding to a specific pH value or providing a numerical readout. B) The pH of a solution can be determined by tasting the solution. C) The pH of a solution can be determined by smelling the solution. D) The pH of a solution can be determined by measuring the temperature of the solution.

Answer: A) The pH of a solution can be determined using pH paper, universal indicator, or pH meter, each showing a color change corresponding to a specific pH value or providing a numerical readout.

Q114: What does a universal indicator do?

A) A universal indicator shows different colors at different pH values, providing a continuous range of colors from 0 to 14 to indicate the acidity or basicity of a solution. B) A universal indicator changes color only at neutral pH. C) A universal indicator changes color only at acidic pH. D) A universal indicator changes color only at basic pH.

Answer: A) A universal indicator shows different colors at different pH values, providing a continuous range of colors from 0 to 14 to indicate the acidity or basicity of a solution.

Q115: How would you use pH paper to determine the pH of an unknown solution?

A) Dip the pH paper into the unknown solution and compare the color change to a pH color chart to determine the pH value. B) Taste the solution and compare it to known pH values. C) Smell the solution and compare it to known pH values. D) Measure the temperature of the solution and compare it to known pH values.

Answer: A) Dip the pH paper into the unknown solution and compare the color change to a pH color chart to determine the pH value.

Q116: What is a common use of sodium chloride in everyday life?

A) Sodium chloride is commonly used as table salt in food. B) Sodium chloride is commonly used as a cleaning agent. C) Sodium chloride is commonly used in car batteries. D) Sodium chloride is commonly used in fertilizer production.

Answer: A) Sodium chloride is commonly used as table salt in food.

Q117: What is a common use of sodium carbonate in everyday life?

A) Sodium carbonate is commonly used as washing soda for cleaning purposes. B) Sodium carbonate is commonly used as baking soda in cooking. C) Sodium carbonate is commonly used as table salt in food. D) Sodium carbonate is commonly used in car batteries.

Answer: A) Sodium carbonate is commonly used as washing soda for cleaning purposes.

Q118: What is a common use of sodium bicarbonate in everyday life?

A) Sodium bicarbonate is commonly used as baking soda in cooking. B) Sodium bicarbonate is commonly used as washing soda for cleaning purposes. C) Sodium bicarbonate is commonly used as table salt in food. D) Sodium bicarbonate is commonly used in car batteries.

Answer: A) Sodium bicarbonate is commonly used as baking soda in cooking.

Q119: How can you distinguish between acidic, basic, and neutral solutions using a universal indicator?

A) Add a few drops of universal indicator to the solution. Acidic solutions turn the indicator red, basic solutions turn it blue, and neutral solutions turn it green. B) Add a few drops of universal indicator to the solution. Acidic solutions turn the indicator blue, basic solutions turn it red, and neutral solutions turn it yellow. C) Add a few drops of universal indicator to the solution. Acidic solutions turn the indicator green, basic solutions turn it red, and neutral solutions turn it blue. D) Add a few drops of universal indicator to the solution. Acidic solutions turn the indicator yellow, basic solutions turn it green, and neutral solutions turn it blue.

Answer: A) Add a few drops of universal indicator to the solution. Acidic solutions turn the indicator red, basic solutions turn it blue, and neutral solutions turn it green.

Q120: What is the role of water in determining the pH of a solution?

A) Water acts as a solvent, allowing the ions to interact and the pH to be measured accurately using indicators or pH meters. B) Water changes the taste of the solution. C) Water changes the color of the solution. D) Water changes the temperature of the solution.

Answer: A) Water acts as a solvent, allowing the ions to interact and the pH to be measured accurately using indicators or pH meters.

Q121: Why is it important to use distilled water for preparing solutions in pH determination experiments?

A) Distilled water is free from impurities and other dissolved substances that could affect the pH reading. B) Distilled water has a different taste compared to tap water. C) Distilled water has a different color compared to tap water. D) Distilled water has a different temperature compared to tap water.

Answer: A) Distilled water is free from impurities and other dissolved substances that could affect the pH reading.

Q122: How does adding water to an acidic or basic solution affect its pH?

A) Adding water to an acidic or basic solution dilutes the solution, bringing the pH closer to neutral (pH 7). B) Adding water to an acidic or basic solution makes the solution more acidic. C) Adding water to an acidic or basic solution makes the solution more basic. D) Adding water to an acidic or basic solution has no effect on its pH.

Answer: A) Adding water to an acidic or basic solution dilutes the solution, bringing the pH closer to neutral (pH 7).

Acid, Bases and salts- Mcqs

Grade VII – Acids, Bases, and Salts

Multiple Choice Questions

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