Question

Separate out exothermic and endothermic process from the following:

$\mathrm{Ice}+\mathrm{Heat}\to \mathrm{Water}$

Answer 1

Energy changes during a reaction:

Reactions can be endothermic or exothermic based on the energies of the reactants and products. Reactions in which the energy of the products is higher than the reactants are called endothermic reactions, and reactions in which the energies of products are lower than the reactants are called exothermic reactions.
In exothermic reactions, the excess energy in the system produced due to the formation of products with lower energy is released in the form of heat. The reactants absorb the extra energy required for the production of higher energy products in endothermic reactions.

Melting of ice:

In the given reaction, ice absorbs heat and forms liquid water $\left({\mathrm{H}}_2\mathrm{O}\right)$. The chemical equation for the phase change is:

$$\begin{gathered} {\mathrm{H}}_2\mathrm{O}\left(\mathrm{s}\right)+\mathrm{Heat}\to {\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \\ \left(\mathrm{ice}\right)\left(\mathrm{water}\right) \end{gathered}$$

Since heat is absorbed by ice to form water, the energy of water is greater than the energy of ice. Therefore, it is an endothermic process.