CIE Chemistry (US-0439): Specimen Questions with Answers 136 - 137 of 240

Question number: 136

Short Answer Question▾

Write in Short

  1. Describe a test, other than measuring pH, which can be carried out on both acid solutions to confirm the explanation given in (b) (i) for the different pH values of the two acids.

Explanation

Question number: 137

MCQ▾

Question

Here are the steps given regarding purification of water for consumption:

Successive filters, Water plants, Settling tanks, Chlorination.

The correct order is:

Choices

Choice (4) Response

a.

b.

c.

d.

Answer

a.

Explanation

First, water from sea or river is brought through pipes to the water plants or water works. Second, this water is stored in ‘settling tanks’ where most of the impurities settle down. Also potash alum is added to enhance sedimentation. Third, the water is made to pass through several filters. Last, the water is then chlorinated and passed for distribution. Chlorination kills majority of microorganisms like bacteria, etc.

Thus the correct order regarding purification of water for consumption is:

Water plants → Settling tanks → Successive filters → Chlorination