Acids, Bases and Salts Class 7 MCQs Questions with Answers
I. Choose the correct option.
Question 1.
Acids taste
(a) sour
(b) sweet
(c) bitter
(d) salty
Answer
Answer: (a) sour
Question 2.
Bases taste
(a) sweet
(b) sour
(c) bitter
(d) salty
Answer
Answer: (c) bitter
Question 3.
Colours of phenolphthalein indicator in acidic and basic medium, respectively are
(a) pink and colourless
(b) colourless and pink
(c) blue and red
(d) red and blue
Answer
Answer: (b) colourless and pink
Question 4.
The nature of bases is
(a) acidic
(b) basic
(c) neutral
(d) all of these
Answer
Answer: (b) basic
Question 5.
Which of the following feel soapy on touching?
(a) Acid
(b) Base
(c) Salt
(d) None of these
Answer
Answer: (b) Base
Question 6.
Which of the following is a natural indicator?
(a) China rose petal
(b) Turmeric
(c) Litmus
(d) All of these
Answer
Answer: (d) All of these
Question 7.
The most commonly used natural indicator is
(a) turmeric
(b) beetroot
(c) China rose petal
(d) litmus
Answer
Answer: (d) litmus
Question 8.
The correct way of making a solution of acid in water is to
(a) add water to acid
(b) add acid to water
(c) mix acid and water simultaneously
(d) add water to acid in a shallow container
Answer
Answer: (b) add acid to water
Question 9.
Which of the following is basic in nature?
(a) Lime water
(b) Baking soda
(c) Both (a) and (b)
(d) Lemon juice
Answer
Answer: (c) Both (a) and (b)
Question 10.
Litmus is extracted from
(a) curd
(b) grapes
(c) lichens
(d) cabbage
Answer
Answer: (c) lichens
Question 11.
Calcium hydroxide is found in
(a) window cleaner
(b) lime water
(c) soap
(d) lime juice
Answer
Answer: (b) lime water
Question 12.
On adding phenolphthalein indicator to a colourless solution, no change is observed. The nature of the solution may be
(a) acidic or basic
(b) basic
(c) acidic or neutral
(d) basic or neutral
Answer
Answer: (c) acidic or neutral
Question 13.
Neutralisation reaction is a
(a) physical and reversible change
(b) physical and irreversible change
(c) chemical and reversible change
(d) chemical and irreversible change
Answer
Answer: (d) chemical and irreversible change
Question 14.
When a drop of vinegar solution is put on the litmus paper, it turns
(a) red
(b) blue
(c) green
(d) yellow
Answer
Answer: (a) red
Question 15.
Tap water is
(a) acidic
(b) basic
(c) neutral
(d) depends on source
Answer
Answer: (d) depends on source
Question 16.
When phenolphthalein is added to a acidic solution, it gives
(a) pink colour
(b) red colour
(c) blue colour
(d) no colour
Answer
Answer: (d) no colour
Question 17.
A neutralisation reaction gives
(a) salt and water
(b) acid and salt
(c) base and salt
(d) acid and base
Answer
Answer: (a) salt and water
Question 18.
Our stomach contains
(a) hydrochloric acid
(b) sodium hydroxide
(c) sulphuric acid
(d) nitric acid
Answer
Answer: (a) hydrochloric acid
Question 19.
When we suffer from acidity, we should take
(a) iron tonic
(b) vitamins
(c) antacid
(d) lactocalamine
Answer
Answer: (c) antacid
Question 20.
When an ant bites, it injects
(a) acidic liquid
(b) basic liquid
(c) both (a) and (b)
(d) neutral liquids
Answer
Answer: (a) acidic liquid
II. Fill in the Blanks
Question 1.
……………. can cause damage to historical monuments, marble, statues, plants and animals.
Answer
Answer: Acid rain
Question 2.
……………. helps to relieve indigestion.
Answer
Answer: Antacid
Question 3.
Organic matters release …………….
Answer
Answer: acids
Question 4.
Salt may be …………… , …………….. or ……………… in nature.
Answer
Answer: acidic, basic, neutral
Question 5.
Plants do not grow well when the soil is either too …………….. or too ……………….
Answer
Answer: acidic, basic
Question 6.
When an ant bites, it injects ………………. acid.
Answer
Answer: formic
Question 7.
Detergent solution is ………………. substance.
Answer
Answer: basic
Question 8.
Chemical name of chuna is ……………….
Answer
Answer: calcium oxide
Question 9.
Phenolphthalein is a ………………. indicator.
Answer
Answer: man-made
Question 10.
The word acid comes from the Latin word ………………. which means ……………….
Answer
Answer: acere, sour
Question 11.
Citrus fruits contain ………………. acid.
Answer
Answer: citric
Question 12.
Milk of magnesia helps to ………………. food.
Answer
Answer: digest
Question 13.
China rose turns acidic solution ………………. and basic solution ……………….
Answer
Answer: dark pink, green
Question 14.
Spinach contains ………………. acid.
Answer
Answer: oxalic
Question 15.
Sugar is ………………. in nature.
Answer
Answer: neutral
III. True or False
Question 1.
Curd is a base.
Answer
Answer: False
Question 2.
Lime juice tastes sour.
Answer
Answer: True
Question 3.
Turmeric is a man-made indicator.
Answer
Answer: False
Question 4.
China rose petal is a natural indicator.
Answer
Answer: True
Question 5.
Litmus is called a natural dye.
Answer
Answer: True
Question 6.
Lactic acid is found in lemons.
Answer
Answer: False
Question 7.
Sodium/Potassium hydroxide is found in soap.
Answer
Answer: True
Question 8.
Litmus paper is available as red and yellow colour.
Answer
Answer: False
Question 9.
Litmus paper turns an acidic solution red and basic solution blue.
Answer
Answer: True
Question 10.
When added to a basic solution, phenolphthalein gives pink colour.
Answer
Answer: True
Question 11.
When the soil is too acidic, it is treated with bases like quick lime.
Answer
Answer: True
Question 12.
Organic matter releases acids.
Answer
Answer: True
Question 13.
A salt is formed when an acid and a base neutralise each other.
Answer
Answer: True
Question 14.
Acids turn blue litmus red.
Answer
Answer: True
Question 15.
Bases turn red litmus green.
Answer
Answer: False
IV. Match the Following
| Column I | Column II |
| 1. Tartaric acid | (a) Soap |
| 2. Calcium hydroxide | (b) Oranges |
| 3. Formic acid | (c) Vinegar |
| 4. Citric acid | (d) Lime water |
| 5. Lactic acid | (e) Tamarind |
| 6. Sodium hydroxide | (f) Window cleaner |
| 7. Oxalic acid | (g) Milk of magnesia |
| 8. Ammonium hydroxide | (h) Curd |
| 9. Acetic acid | (i) Ant’s sting |
| 10. Magnesium hydroxide | (j) Spinach |
Answer
Answer:
| Column I | Column II |
| 1. Tartaric acid | (e) Tamarind |
| 2. Calcium hydroxide | (d) Lime water |
| 3. Formic acid | (i) Ant’s sting |
| 4. Citric acid | (b) Oranges |
| 5. Lactic acid | (h) Curd |
| 6. Sodium hydroxide | (a) Soap |
| 7. Oxalic acid | (j) Spinach |
| 8. Ammonium hydroxide | (f) Window cleaner |
| 9. Acetic acid | (c) Vinegar |
| 10. Magnesium hydroxide | (g) Milk of magnesia |
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