Chemistry MCQs

Question 1

Potassium Permanganate is used for purifying drinking water, because________

Accepted Answer

It is an oxidising agent

Answer

It is a reducing agent

Answer

It is a sterilising agent

Answer

It dissolves the impurities of water

Question 2

Lead in water can cause

Accepted Answer

Kidney damage

Answer

Eye disease

Answer

Arthritis

Answer

Hair falling

Question 3

Hardness of the water is commonly measured in terms of

Accepted Answer

Calcium carbonate equivalents

Answer

Calcium sulphate equivalents

Answer

Magnesium carbonate equivalents

Answer

Magnesium sulphate equivalents

Question 4

Maximum permissible concentration of copper in drinking water in mg/L is

Accepted Answer

1

Answer

0.01

Answer

0.05

Answer

2

Question 5

The amount of chlorine available in water after disinfection is called as

Accepted Answer

Residual chlorine

Answer

Free chlorine

Answer

Free available chlorine

Answer

Combined available chlorine

Question 6

Maximum permissible concentration of total hardness in drinking water is

Accepted Answer

200

Answer

50

Answer

100

Answer

500

Question 7

Which one of the following is extensively used for sterilizing water ?

Accepted Answer

Bleaching powder

Answer

Alum

Answer

Borax powder

Answer

Soda powder

Question 8

Assertion (A) : Synthetic detergents can lather when in hard water.Reason (R) : Synthetic detergents form soluble calcium and magnesium salts with hard water.

Accepted Answer

Both A and R is true and R is the correct explanation of A

Answer

Both A and R is true but R is not a correct explanation of A

Answer

A is true but R is false

Answer

A is false but R is true

Question 9

Where does the oxygen that keeps us alive come from?

Accepted Answer

Water

Answer

Carbon dioxide

Answer

Carbonates absorbed from soil

Answer

Oxides of minerals