Check sibling questions

Question 1

Neutralisation reaction is a :

  1. Physical and reversible change
  2. Physical change which is not reversible
  3. Chemical and reversible change
  4. Chemical change which is not reversible

 

Answer: 

Neutralisation reaction is a chemical reaction between an acid and a base that produces salt and water. 

It is irreversible in nature.

Neutralization reaction.jpg

Therefore the answer is (d).

 

Question 2

The acid present in Amla is:

  1. Malic acid
  2. Tartaric acid
  3. Citric acid
  4. Ascorbic acid

 

Answer:

Amla contains Ascorbic acid in it.

Therefore the answer is (d).

 

Question 3

Phenolphthalein is a synthetic indicator and its colours in acidic and basic solutions respectively are:

  1. Red and blue
  2. Blue and red
  3. Pink and colourless
  4. Colourless and pink

 

Answer:

Phenolphthalein is an indicator that changes its colour to pink when exposed to a basic solution.

When an acidic solution is added to it, it experiences no change in colour.

Therefore the answer is (d)

 

Question 4

The correct way of making a solution of acid in water is:

  1. Add water to acid
  2. Add acid to water
  3. Mix acid and water simultaneously
  4. Add water to acid in shallow container

 

Answer:  

  • We should always very carefully add acid to water .
  • Diluting an acidic or basic solution is a reaction that produces a lot of heat .
  • Mixing acid and water simultaneously or adding water to acid could actually trigger a blast of water and acid on the user.

Therefore the answer is (b).

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Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 12 years and a teacher from the past 16 years. He teaches Science, Economics, Accounting and English at Teachoo