Question

When ice at -10 degree celsius is slowly heated ,the temperature of ice gradually increases till 0 degree celsius, the temperature of the system remains constant when the ice changes into water and then further rises. explain the observation

Answer 1

Dear student,

The melting point of ice is $0^{0}C$ /273.15K,therefore if ice is heated below this temperature melting point of
ice will increase when heated but the moment it is reached 273.15K,the temperature stops rising.
The melting of ice is called Phase Transition.
Whenever energy is used for phase transition,the temperature remains constant.
It can also be explained on the basis of the formula :
Q=mcΔT where Q is heat,m is the mass,c is the heat capacity and ΔT is temperature difference.Q=mc∆T where Q is heat,m is the mass,c is the heat capacity and ∆T is temperature difference.
Now,when we start heating ice,the given equation follows that is as long as no phase change takes place
,the equation holds.
When the ice reaches 0 degree Celsius, the ice gets too warm to hold its solid state and it starts to melt which
means now there will be phase change from solid to liquid. Since there is phase change therefore during this period temperature will be constant.
When the whole of the ice gets converted to liquid state, then again temperature starts rising because of new state that
is liquid state following the above equation.

Regards