if 1kg of ice at 0 degree celcius is to be converted into 1kg of water at 0 degree how can it be converted,as the freezing point is 0 degree and water gets converted to ice at this temp.
The freezing point or melting point of water is the temperature at which water changes phase from a liquid to a solid or vice versa.
The freezing point describes the liquid to solid transition while the melting point is the temperature at which water goes from a solid (ice) to liquid water.
In theory, the two temperatures (freezing point and melting point of water) would be the same that is 0° C or 32° F, but liquids can be supercooled beyond their freezing points so that they do not solidify until well below freezing point.
Here 1 kg ice is in solid phase hence at 0 degree it starts melting (starts to get converted to liquid phase) and this 0 degree would be melting point of ice and not freezing point here.