Phase change energy

[406003397]

How do you calculate the energy required for the phase change of a substance without changing its temperature, specifically when converting ice at 0°C to water at 0°C? Could you explain the use of specific heat and heat of fusion in this context

[CristinaG]

The heat energy required for a phase change from solid to liquid is modeled by the equation: q = m*deltaH(fusion). So, in order to solve for q, you need to know the mass of ice that you have and the heat of fusion of ice. You do not need to know the specific heat, that's only used when there is a temperature change. When you do have a temperature change, that's when you would use the formula q=m*c*deltaT, which needs the specific heat.

[Soobin Lim 2B]

We use the concept of latent heat of fusion (or heat of fusion). The heat of fusion is the amount of energy required to change the phase of a substance from solid to liquid (or vice versa) at its melting/freezing point, without any change in temperature. For water, the latent heat of fusion is 334 kJ/kg and to find the energy required (Q) to convert a mass (m) of ice at 0°C to water at 0°C, we use the equation: Q = m × L, where L is the latent heat of fusion for water (334,000 J/kg). This equation accounts for the energy needed for the phase change without any temperature change.