Q.1 Statements:

1) Soaps can lather well in hard & soft water

2) Synthetic detergents form soluble calcium & magnesium salts with hard water.

3) Hard water contains chloride & sulphate salts of Magnesium & Calcium

Options:

A) 1 & 2

B) Only 3

C) 1,2,3

D) 2 & 3

Ans. D

Q.2 statements:

1) sulphur dioxide & Nitrogen dioxide contribute to Acid Rain.

2) Oxides of carbon emitted from coal burns contribute to acid rain.

Options:

A) Only 1

B) Only 2

C) Both are correct

D) Both are incorrect

Ans. A

Q.3 Why the aqueous solution of copper sulphate is acidic in nature ?

A) Because salt undergoes electrolysis

B) Because salt undergoes Photolysis

C) Because salt undergoes dialysis

D) Because salt undergoes hydrolysis

Ans. D

Q.4 Hard Water is not  suitable for :

1) drinking

2) Washing clothes

3) use in boilers

4) irrigating crops

Codes:

A) 1 & 4

B) 1 & 2

C) 2 & 3

D) 1,2,4

Ans. C

Q.5 consider the following statements:

1) Polluted water has high Biological Oxygen Demand.

2) Water pollution in river is measured by dissolved amount of Chlorine.

Codes:

A) Only 1

B) Only 2

C) Both are correct

D) Both are incorrect

Ans. A