Question

In case of a burn you would use?

• Ice at [email protected]
• Water at [email protected]

Solution:

The first question many students asked us was:

How can water exist at [email protected]? How can ice exist at [email protected]?

Melting and boiling point of water is not fixed and there many factors which influence it like the pressure applied, presence of impurities. So it possible to raise, lower the melting point of water.

Now coming back to the question. We need to find the material which is going to absorb more energy.

Specific heat of water if 4.2J/g while the latent heat of ice is 330J/g.

While taking water from [email protected] to [email protected] will absorb 12*4.2=50.4J

But converting ice to water at [email protected] will require 330J.

So Ice at 10C appears much colder than water at [email protected]