Question

state reasons why we use Mercury and alcohol in the thermometer​

Answer 1

because of high cofficient of expansion. mercury and alcohol is used in thermometer because they expand at a fixed rate when it is heated , hence a slight change in temperature will increase the expansion a long way up the tube..

Answer 2

So The reason behind using Mercury as a Thermometric Liquid:-

1. It has low specific heat capacity.

2. Its expansion is uniform.

3. It has high b.p.(357 °C) and low m.p.(-39°C).

4. It is opaque and shining.

5. It does not stick to the sides of the glass.

6. It exerts very low vapour pressure.

7. It is a good conductor of heat.

8. It is easily available in pure state.

Again, Reason behind using Alcohol as Thermometric Liquid:-

1. Its freezing point is below -100°C and hence can record very low temperatures.

2. Its expansion per degree centigrade rise in temperature is very large hence, very sensitive thermometers can be made with it.

3. It can be coloured brightly and hence, is easily visible.