CBSE Class 7 Science Acids Bases and Salts MCQs

Acids, Bases, and Salts

Question. Acids are 
(a) Sour in taste
(b) Sweet in taste
(c) salty in taste
(d) Bitter in taste

Answer: A

Question. Bases are 
(a) Sour in taste
(b) Sweet in taste 
(c) salty in taste 
(d) Bitter in taste

Answer: D

Question. The substances that are used to test whether a substance is acidic or basic is called 
(a) Indicator
(b) Acid 
(c) Base
(d) Salt

Answer: A

Question. Give the chemical name of Lime water
(a) Calcium hydroxide
(b) Magnesium hydroxide
(c) Ammonium hydroxide 
(d) Sodium hydroxide 

Answer: A

Question. Give the chemical name of Milk of magnesia 
(a) Calcium hydroxide
(b) Magnesium hydroxide 
(c) Ammonium hydroxide
(d) Sodium hydroxide 

Answer: B

Question. Give the chemical name of Window cleaner
(a) Calcium hydroxide
(b) Magnesium hydroxide 
(c) Ammonium hydroxide 
(d) Sodium hydroxide 

Answer: C

Question. Litmus paper (purple colour) in distilled water when added to an acid changes to 
(a) Red
(b) Blue
(c) Green
(d) Violet 

Answer: A

Question. The solutions which do not change the colour of either red or blue litmus are known as 
(a) Acid Solutions
(b) Base Solutions 
(c) Neutral Solutions
(d) indicator 

Answer: C

Question. Find the natural indicator from the following
(a) China Rose
(b) Vinegar 
(c) Phenolphthalein
(d) Methyl Orange

Answer: A

Question. Phenolphthalein gives ____________colour in acid medium 
(a) Pink
(b) Colourless 
(c) Green
(d) Red

Answer: A

Question. The sting of an ant contains ___________. 
(a) Hydrochloric acid
(b) Formic acid 
(c) sulphuric acid
(d) Ethanoic acid

Answer: B

Question. The effect of sting of an ant can be neutralised by rubbing with
(a) Calcium carbonate
(b) Sodium Carbonate 
(c) Sodium hydrogen carbonate 
(d) Calciumchloride 

Answer: C

Question. Blue litmus paper is dipped in a solution. It remains blue. What is the nature of solution ?
(a) Acid and base
(b) Base and neutral
(c) Acid apd neutral
(d) None of these

Answer:  B

Question. Which feels soapy on touch ?
(a) Acids
(b) Bases
(c) Both (a) and (b)
(d) None of these

Answer:  B

Question. Litmus is extracted from
(a) curd
(b) grapes
(c) lichens
(d) cabbage

Answer:  C

Question. Process in which acids and bases react to form salt and water is called
(a) neutralisation
(b) hydrogenation
(c) sublimation
(d) all of these

Answer:  C

Question. On adding phenolphthalein indicator to a colourless solution, no change is observed. What is the nature of this solution?
(a) Basic
(b) Either acidic or basic
(c) Either acidic or neutral
(d) Either basic or neutral

Answer:  C

Question. Acid used in eye wash is
(a) carbonic acid
(b) acetic acid
(c) benzoic acid
(d) boric acid

Answer:  D

Question. When CO2 gas is passed through limewater, it turns milky. Which of the following compounds is responsible for this milkiness ?
(a) Calcium oxide
(b) Calcium chloride
(c) sodium carbonate
(d) Calcium carbonate

Answer:  D

Question. Turmeric is a natural indicator. On adding its paste to acid and base separately, which colours would be observed.
(a) Yellow in both acid and base
(b) Yellow in acid and red in base
(c) Pink in acid and yellow in base
(d) Red in acid and blue in base

Answer:  B

Question. Acids taste
(a) sour
(b) sweet
(c) bitter
(d) salty

Answer:  A

Question. Neutralisation reactioñ is a
(a) physical and reversible change
(b) physical and irreversible change
(c) chemical and reversible change
(d) chemical and irreversible change

Answer:  D

Question. How will you classify the reaction between NaOH (aq) and HCl (aq)?
(a) Conbination
(b) Displacement
(c) Dissociation
(d) Neutralisation

Answer:  D

Question. When we suffer from acidity, we should take
(a) iron tonic
(b) vitamins
(c) antacid
(d) lactocalamine

Answer:  C

Question. The nature of bases is
(a) acidic
(b) basic
(c) neutral
(d) all of these

Answer:  B

Question. Common salt is
(a) acidic
(b) basic
(c) neutral
(d) none of these

Answer:  C

Question. The acid that our stomach releases is:
(a) sulphuric acid
(b) nitric acid
(c) hydrochloric acid
(d) formic acid

Answer:  C

Question. The most commonly used natural indicator is
(a) turmeric
(b) beetroot
(c) China rose petal
(d) litmus

Answer:  D

Question. In neutralisation reaction:
(a) heat is absorbed
(b) heat is evolved
(c) neither heat is absorbed nor evolved
(d) none of these

Answer:  B

Question. When phenolphthalein is added to a acidic solution, it gives
(a) pink colour
(b) red colour
(c) blue colour
(d) no colour

Answer:  D

Question. Neutralisation is a reaction between
(a) two acids
(b) two bases
(c) one acid and one base
(d) one acid and one neutral substance

Answer:  C

Question. Which of the following substances makes the fruits sound.
(a) Acids
(b) Salts
(c) Bases
(d) None of these

Answer:  A

Question. The colour of litmus in distilled water is:
(a) red
(b) green
(c) blue
(d) purple

Answer:  D

Question. Ammonia that turns red litmus blue is:
(a) acidic
(b) basic
(c) neutral
(d) none of these

Answer:  B

Question. If the soil is too basic, it is treated with:
(a) quicklime
(b) salt
(c) organic matter
(d) water

Answer:  C

Question. Which of the following turns colourless solution of phenol¬phthalein into pink solution ?
(a) Salt
(b) Base
(c) Acid
(d) All of these

Answer:  B

Question. Magnesium hydroxide is found in:
(a) soap
(b) lime water
(c) milk of magnesia
(d) vegetable

Answer:  C