Question

What are your observations and conclusions when tap water is boiled and evaporated in watch glass?

Answer 1

Tap water is contaminated water, contaminated in the sense it might contain impurities as it is water from the source. This tap water has a high chance of containing a minimal amount of chlorine. It is often added to control and prevent the growth of different kinds of bacteria while this water courses through the pipes from the source. Source water most generally consists of minerals and some inorganic compounds like calcium.

Complete Step By Step Answer:
Our observation would be, at the point when tap water is bubbled and dissipated in a watch glass, we can notice certain concentric rings of the that tap water contains disintegrated salts in it. Some people also boil water in order to kill the already present microorganisms, like bacteria, viruses and protozoans that can cause different diseases. Hence these people believe boiling tap water makes it microorganism free and hence disease free.
In conclusion, boiling tap water makes it microorganism free. It also shows some rings around the watch glass hinting that there were certain gases and impurities present in the said water.

Note:
The tap water when evaporated shows there are rings concentrated on the sides of the watch glass hinting the presence of solid matter in it. We can conclude it contains dissolved minerals, salts and some impurities. It can also be seen that it contains trace amounts of chlorine so as to eliminate contagious diseases by eliminating harmful microorganisms.