Water changes to ice at

(a)

0⁰C

(b)

100⁰C

(c)

102⁰C

(d)

98⁰C

Solubility of carbon dioxide in water is high when the

(a)

pressure is low

(b)

pressure is high

(c)

temperature is high

(d)

None of the above

The gas collected at the cathode on electrolysis of water is

(a)

oxygen

(b)

hydrogen

(c)

nitrogen

(d)

carbon dioxide

Which of the following is a water pollutant?

(a)

Lead

(b)

Alum

(c)

Oxygen

(d)

Chlorine

Permanent hardness of water is due to the presence of __________

(a)

Sulphates and Chlorides

(b)

Dust particles

(c)

Carbonates and Bicarbonates

(d)

Other soluble particles