Question

205. The chlorine demand of a water sample was found to be 0.2 mg/l. The amount of bleaching powder containing 30% available chlorine to be added to treat one litre of such a water sample is:
a) 0.67 mg
b) 0.06 mg
c) 1.33 mg
d) 0.14 mg
[ES 94]​

Answer 1

Hii Manoj,

◆ Answer -

(a) 0.67 mg

● Explanation -

Let X be the amount of bleaching powder to be added in 1 L water.

Chlorine requirement is calculated by -

Chlorine requirement = chlorine demand × volume of water

Chlorine requirement = 0.2 × 1

Chlorine requirement = 0.2 mg

Amount of bleaching powder is calculated by -

Bleaching powder = chlorine requirement / availability

Bleaching powder = 0.2 / 30%

Bleaching powder = 0.2 × 100 / 30

Bleaching powder = 0.67 mg

Therefore, 0.67 mg of bleaching powder will be required to treat 1 L water.

Hope that's all...

Answer 2

Answer:

A is the correct answer i.e 0.67 mg