Question

(a) You are given a glass full of muddy water. The steps you should take to get clear water from it are listed below. Arrange these steps in the correct order.
(i) Line a funnel with filter paper or cloth.
(ii) Allow the water to stand, without disturbing it.
(iii) Gently pour out the liquid portion into another glass.
(iv) Throw away the thick muddy water left behind in the first glass.
(v) Pour the water into the funnel.
(vi) The mud particles, being heavier, will settle at the bottom.
(vii) Collect the clear water that comes through the funnel.
(b) Give a single word that explain the steps described in ii and v.
(c) What else can you do to help remove the mud particles from the water? What is this process called?
(d) Do you think this water is now safe to drink? Why?
(e) Name one simple way be which this water can be made safe for drinking.

Answer 1

(a) The correct order is as follows:
(ii) Allow the water to stand, without disturbing it.
(vi) The mud particles, being heavier, will settle at the bottom.
(iii) Gently pour out the liquid portion into another glass.
(iv) Throw away the thick muddy water left behind in the first glass.
(i) Line a funnel with filter paper or cloth.
(v) Pour the water into the funnel.
(vii) Collect the clear water that comes through the funnel.

(b) Steps (ii) and (v) are sedimentation and filtration, respectively.

(c) The mud particles can be settled and removed by adding alum. This process is called loading.

(d) This water is not fit for drinking as it still has disease-causing bacteria and germs.

(e) By boiling, this water can be made fit for drinking. Boiling of water will kill all the germs.