Question

1 gram of ice which on melting forms 1 gram of water absorbs 80 calories of energy.
A.) True
B.) False

Answer 1

Hint: Try to recall that the amount of thermal energy required to cause a solid to melt into liquid without any change in energy is called latent heat. Now by using this you can easily find whether the given statement is true or false.

Complete step by step solution:
It is known to you that latent heat of fusion is the amount of heat required to change the state of a substance from solid to liquid without any change in temperature.
The temperature at which this happens is known as the melting point of that substance.
For water, latent heat of fusion is the amount of heat energy released when ice at 273 K gets converted into water.
It has been seen experimentally that the latent heat of fusion for water is about 80 calorie i.e. when 1 gram of ice melts to 1 gram of ice, then it releases 80 calorie of energy.
Therefore, from above we can conclude that the given statement is true and option A is the correct option for the given statement.

Note: It should be remembered to you that latent heat of evaporation is the amount of energy required to change the state of a substance from liquid to vapour without any change in temperature.
Also, you should remember that 1 gram of water on vaporisation forms 1 gram of vapour and absorbs 539 calories of energy.