Question

The heat of fusion for water is$80cal/g$. How many calories of heat are needed to melt a $35g$ ice cube that has a temperature of$0^\circ C$?

Answer 1

The enthalpy of fusion of a substance, otherwise called latent heat of fusion is the adjustment in its enthalpy from giving energy, especially heat, to a particular amount of a substance to change its state from solid to liquid, at constant pressure. For instance, to liquefy $1Kg$of ice (at$0^\circ C$ under a wide range of pressure) $333.55KJ$of energy is caught up with no temperature change. The heat for solidification (when a substance changes its state from fluid to solid) is equivalent and inverse.

Complete answer:
The enthalpy of fusion is the latent heat in light of the fact that during liquefying the heat energy expected to change the substance from solid to liquid at atmospheric pressure is the latent heat of fusion, as the temperature stays steady during the cycle. The latent heat of fusion is the enthalpy change of any measure of substance when it liquefies. At the point when the heat of is referred to a unit mass, it is generally called the specific heat of fusion, while the molar heat of fusion alludes to the enthalpy change per measure of substance in moles.
The formula required to liquefy or melt a solid is:
$q = m\Delta H_{fusion}^o$
q$$$$ = The amount of heat required
m$$$$ = Mass of the solid substance
\Delta H_{fusion}^o$$$$ = The enthalpy of fusion which is also called the latent heat of fusion
From the question, the given data is,
$\Delta H_{fusion}^o = 80cal/g$
$\therefore q = 35g \times 80cal/g = 2800cal = 2.8 \times {10^3}cal$
So, we will get $2.8 \times {10^3}cal$is required to melt $35g$of an ice cube.

Note: Solids can be heated to where the atoms holding their bonds together split up and structure a fluid. The most well-known example would be solid ice transforming into liquid water. This cycle is otherwise called liquefying and results in the particles inside the substance getting less coordinated. At the point when a substance changes over from a strong solid state to liquid, the adjustment in enthalpy is always positive.