Acids, Bases And Salts Worksheet

Objective Type Questions

1. Match the ‘Name of Acid/Base’ mentioned in column A with the items in which they are present given in column B ‘Found in’.
   
   
   
2. State whether the following statements are true or false. In case of false statement, write the correct one.
   (i) Acids and bases can be identified by tasting it directly.
   (a) True
   (b) False
   
   (ii) Neutralisation reaction occurs by absorption of heat.
   (a) True
   (b) False
   
   Multiple Choice Questions
   
   
3. Due to vitamin C deficiency, Jayesh’s doctor advised him to drink lemon juice without sugar in the morning. However, he didn't enjoy the normal taste of lemon juice without sugar. What taste must lemon juice have?
   
   
   (a) Sweet
   (b) Bitter
   (c) Sour
   (d) Tasteless
   
   
4. Renu added phenolphthalein indicator to acetic acid solution. The colour of the solution will be:
   
   (a) Blue
   (b) Red
   (c) Colourless
   (d) Pink
   
   
5. While brewing the tea, Arun accidentally substituted baking soda for the sugar. The taste of tea is:
   
   (a) Sour
   (b) Bitter
   (c) Sweet
   (d) Tasteless
   
   
6. Sagar's mother made it mandatory for him to brush his teeth twice a day because he had a tendency of consuming a lot of chocolates. The nature of toothpaste used here, must be:
   
   (a) Acidic
   (b) Alkaline
   (c) Neutral
   (d) None of the above
   
   
7. During her visit to a zoo, Sevanthi had an ant sting. From the options below, pick the best treatment for her.
   
   (a) Calamine solution
   (b) Lemon juice
   (c) Common salt
   (d) Sugar syrup
   
   
8. Litmus is extracted from ____________.
    
   (a) Lichi
   (b) Lantana
   (c) Lichen
   (d) Lavender
   
   
9. Name the acid present in DNA.
   (a) Deoxyribonucleic acid
   (b) Ribonucleic acid
   (c) Tartaric acid
   (d) Dichlorophenoxyacetic acid
   
   
10. Distilled water was sent to chemistry laboratory to check its acidity/alkalinity. What should be its effect on litmus paper?  Select the correct option.
    
    
    
    
    
    Case Study Questions
    
    
11. Acid rain is an indirect product of climate change. Only a small portion of the emissions that are required for the formation of acid rains are generated naturally and the majority of them are the result of human activities that involve burning fossil fuels.
    
    
    (a) Define acid rain.
    (b) What are the causes of acid rain?
    (c) Mention any two other hazardous effects of the same phenomenon.
    
    Subjective Questions
    
    
12. Factories surrounding the Taj Mahal were either shut down or shifted elsewhere. What must have been the reason for it?
    
    
13. Classify below objects as acids, bases and Neutral.
    Lemon, Antacids, Baking soda, Soap, Salt, Toothpaste, Curd, Oranges, Lime water.
    
    
14. Write the name of compound present and the nature of it as acid/base/neutral.
    
    

    Objects	Name of the compound	Acid/Base/Neutral

15. Sunil was surprised to find that despite adequate rainfall and additional fertilisers, the crop quality from the previous year was poor. An analysis of the soil showed that it had become extremely acidic. How can acidity in the soil be decreased?
    
    
    
16. Shiwani accidentally poured distilled water rather than hydrochloric acid to the beaker containing the acid. Will the nature of the solution alter? Comment.
    
17. Rashmi’s mother warned her not to put her clothing dyed with turmeric in soap water for washing.  Give the reason for the same.
    
18. Differentiate between acids and bases.
    
    Assertion Reasoning Questions
    
    Below questions consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
    
    
    
    
19. Assertion (A): The reaction between an acid and a base is termed as neutralisation reaction.
    Reason (R): The neutralisation reaction produces salt and water.
    
    
20. Assertion (A): An acid turns blue litmus red and a base turns red litmus blue.
    Reason(R): The substance which is neither acid nor base is termed as neutral.

Objective Type Questions

1. Match the ‘Name of Acid/Base’ mentioned in column A with the items in which they are present given in column B ‘Found in’.
   
   Solution:
   
   
   
2. State whether the following statements are true or false. In case of false statement, write the correct one.
   (i) Acids and bases can be identified by tasting it directly.
   (a) True
   (b) False
   
   (ii) Neutralisation reaction occurs by absorption of heat.
   (a) True
   (b) False
   
   Solution:
   (i) Correct option: (b) False.
   Acids and bases should never be tasted directly for identification, as most of them are hazardous and toxic.
   
   (ii) Correct option: (b) False
   Neutralisation reaction occurs by evolution of heat.
   
   Multiple Choice Questions
   
   
3. Due to vitamin C deficiency, Jayesh’s doctor advised him to drink lemon juice without sugar in the morning. However, he didn't enjoy the normal taste of lemon juice without sugar. What taste must lemon juice have?
   
   
   (a) Sweet
   (b) Bitter
   (c) Sour
   (d) Tasteless
   Correct option: (c) Sour
   Solution: Lemon juice has sour taste due to the presence of citric acid in it.
   
   
4. Renu added phenolphthalein indicator to acetic acid solution. The colour of the solution will be:
   
   (a) Blue
   (b) Red
   (c) Colourless
   (d) Pink
   Correct option: (c) Colourless
   Solution: Colour of phenolphthalein indicator in acidic solution is colourless and in alkaline solution, is pink.
   
   
5. While brewing the tea, Arun accidentally substituted baking soda for the sugar. The taste of tea is:
   
   (a) Sour
   (b) Bitter
   (c) Sweet
   (d) Tasteless
   Correct option: (b) Bitter
   Solution: Baking soda is weakly basic in nature, hence it tastes bitter.
   
   
6. Sagar's mother made it mandatory for him to brush his teeth twice a day because he had a tendency of consuming a lot of chocolates. The nature of toothpaste used here, must be:
   
   (a) Acidic
   (b) Alkaline
   (c) Neutral
   (d) None of the above
   Correct option: (b) Alkaline
   Solution: When we eat chocolates, small pieces of it stick to our teeth. The bacteria present in our mouth starts decaying the food particles as a result of which small amount of acid is produced. This acid decreases the pH of the mouth and results in the decaying of tooth enamel. In order to neutralise this acid, toothpaste must be alkaline.
   
   
7. During her visit to a zoo, Sevanthi had an ant sting. From the options below, pick the best treatment for her.
   
   (a) Calamine solution
   (b) Lemon juice
   (c) Common salt
   (d) Sugar syrup
   Correct option: (a) Calamine solution
   Solution:  Ant’s venom contains methnoic acid. It can be neutralised by alkaline calamine solution that consists of zinc carbonate, which is alkaline.
   
   
8. Litmus is extracted from ____________.
    
   (a) Lichi
   (b) Lantana
   (c) Lichen
   (d) Lavender
   Correct option: (c) Lichen.
   Solution: Litmus is a natural indicator, which is extracted from plants named as Lichens.
   
   
9. Name the acid present in DNA.
   (a) Deoxyribonucleic acid
   (b) Ribonucleic acid
   (c) Tartaric acid
   (d) Dichlorophenoxyacetic acid
   Correct option: (a) Deoxyribonucleic acid
   Solution: DNA consists of Deoxyribonucleic Acid, hence it is termed as DNA.
   
   
10. Distilled water was sent to chemistry laboratory to check its acidity/alkalinity. What should be its effect on litmus paper?  Select the correct option.
    
    
    
    
    Correct option: (d) Blue Litmus - Remains unchanged, Red Litmus - Remains unchanged
    Solution: Distilled water is neutral in nature, hence the colour of both blue and red litmus papers would remain unchanged.
    
    Case Study Questions
    
    
11. Acid rain is an indirect product of climate change. Only a small portion of the emissions that are required for the formation of acid rains are generated naturally and the majority of them are the result of human activities that involve burning fossil fuels.
    
    
    (a) Define acid rain.
    (b) What are the causes of acid rain?
    (c) Mention any two other hazardous effects of the same phenomenon.
    Solution:
    (a) The rain which contains a higher level of acid than normal is called acid rain.
    (b) The rain becomes acidic because carbon dioxide, sulphur dioxide and nitrogen dioxide (which are released into the air as pollutants) dissolve in rain drops to form carbonic acid, sulphuric acid and nitric acid respectively.
    (c) Hazardous effects of acid rain:
    Acid rain can cause damage to buildings, historical monuments, plants and animals. Aquatic living organisms are very prone to the damage due to acid rain.
    
    Subjective Questions
    
    
12. Factories surrounding the Taj Mahal were either shut down or shifted elsewhere. What must have been the reason for it?
    
    Solution: The marble of Taj Mahal was getting deteriorated due to acid rain. The rain becomes acidic because carbon dioxide, sulphur dioxide and nitrogen dioxide (which are released into the air as pollutants) dissolve in raindrops to form carbonic acid, sulphuric acid and nitric acid respectively. The smoke coming from factories consists of the gases such as oxides if carbon, nitrogen and sulphur which on dissolution in rain water form acid rain responsible for damage to the marble of Taj Mahal.
    
    
13. Classify below objects as acids, bases and Neutral.
    Lemon, Antacids, Baking soda, Soap, Salt, Toothpaste, Curd, Oranges, Lime water.
    Solution:
    
    

    Acids	Bases	Neutral
    Lemon	Antacids	Salt
    Curd	Baking soda
    Oranges	Soap
    	Toothpaste
    	Lime water

14. Write the name of compound present and the nature of it as acid/base/neutral.
    
    

    Objects	Name of the compound	Acid/Base/Neutral

    Solution:
    
    

    Objects	Name of the compound	Acid/Base/Neutral
    	Magnesium hydroxide	Basic
    	Acetic acid	Acidic
    	Sucrose	Neutral
    	Ammonium hydroxide	Basic
    	Oxalic acid	Acidic

15. Sunil was surprised to find that despite adequate rainfall and additional fertilisers, the crop quality from the previous year was poor. An analysis of the soil showed that it had become extremely acidic. How can acidity in the soil be decreased?
    
    Solution: Excessive use of chemical fertilisers makes the soil acidic.  Plants do not grow well when the soil is either too acidic or too basic. When the soil is too acidic, it is treated with bases like quick lime (calcium oxide) or slaked lime (calcium hydroxide).
    
    
16. Shiwani accidentally poured distilled water rather than hydrochloric acid to the beaker containing the acid. Will the nature of the solution alter? Comment.
    
    Solution: The final nature of the HCl solution after adding distilled water would not alter because distilled water is neutral in nature.
    
    
17. Rashmi’s mother warned her not to put her clothing dyed with turmeric in soap water for washing.  Give the reason for the same.
    
    Solution: In a basic solution, turmeric turns from yellow to red in colour. The soap solution is basic in nature. As a result, the turmeric-dyed fabric would turn red in hue. Therefore, clothing that has been coloured with turmeric should never be washed in soapy water.
    
    
18. Differentiate between acids and bases.
    Solution:
    

    	Acid		Base
    I	Acids have sour taste.	i	Bases have bitter taste.
    Ii	Acids turn moist blue litmus red.	ii	Bases turn moist red litmus blue.
    iii	Phenolphthalein gives pink colour in acidic solution.	iii	Phenolphthalein remains colourless in basic solution.
    Iv	Methyl orange indicator turns red in acidic solution.	iv	Methyl orange indicator is yellow in basic solution.
    V	Examples: Lime, Soda water	v	Examples: Baking soda, Soap solution

    
    Assertion Reasoning Questions
    
    Below questions consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
    
    
19. Assertion (A): The reaction between an acid and a base is termed as neutralisation reaction.
    Reason (R): The neutralisation reaction produces salt and water.
    Correct option: (a) Both A and R are true and R is the correct explanation of A.
    Solution: The reaction between an acid and a base is known as neutralisation since salt and water are produced in this process with the evolution of heat. Thus, in the neutralisation reaction, acid neutralises base and vice versa.
    Acid + Base → Salt + Water. Thus, reason is the correct explanation of assertion.
    
    
20. Assertion (A): An acid turns blue litmus red and a base turns red litmus blue.
    Reason(R): The substance which is neither acid nor base is termed as neutral.
    Correct answer: (b) Both A and R are true and R is not the correct explanation of A.
    Solution: Assertion and reason both are facts but reason is not the explanation of assertion.