Question

If you add heat slowly to ice at 0°C, why doesn't the temperature of the ice increase? What becomes of this heat energy? Likewise, if you add heat to boiling water, the temperature remains at 100°C. What is happening to the heat you add?

Temperature and Heat Conceptual Question...Please answer the question directly with brief explanation. will rate based on clarity and explanation...Thank you!!

Answer 1

If you add heat to ice at 0C, its temperature doesnot increase until it melts because

Latent heat of Fusion: is the heat to a specific quantity of the substance to change its state from a solid to a liquid at constant pressure. (or)

The temperature at which the phase transition occurs is the melting point

for water, its value is 334000 J/kg

At first we have to provide that energy for the ice to melt to water. if you provide energy further its temperature rises.

q = mass of ice * latent heat of fusion [ice comletely converts into water which on further heating increases the temperature]

same is with Boiling point

Latent heat of vapourisation: is the energy (enthalpy) that must be added to the liquid substance, to transform a quantity of that substance into a gas. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.

at 100 C all the water that is heated is at 100 C (saturation state), which on further heating turns into vapor.

if all the quantity is to be turned into vapor

q to be supplied = mass of water * latent heat of vaporisation [after heating it to 100C]