Question

In which of the following heat energy will be evolved?
$1)$ Electrolysis of water
$2)$ Dissolution of $N{H_4}Cl$ in water
$3)$ Burning of LPG
$4)$ Decomposition on $AgBr$ in the presence of sunlight

Answer 1

Hint: The movement of tiny particles called atoms, molecules, or ions in solids, liquids, and gases produces heat energy. It is possible to transfer heat energy from one object to another. Heat is the movement or flow of energy caused by a temperature difference between two objects.

Complete answer:
Option \[1\]: This is not the correct option because electrolysis is the process of breaking down water into oxygen and hydrogen gas using electricity. This hydrogen gas can be used as hydrogen fuel, or it can be combined with oxygen to make oxyhydrogen gas, which is used in welding and other applications. This process absorbs heat.
Option $2$: This is not the correct option. Although the dissolution of $N{H_4}Cl$ in water is endothermic, it dissolves because it absorbs heat from the environment to overcome lattice energy and hence dissolves, despite the fact that the process is endothermic and $\Delta S$ is positive.
Option $3$: This is the correct option because It's a chemical reaction that produces carbon dioxide, fire, and water when a hydrocarbon is burned.
Option $4$: This is not the correct option because in the presence of sunlight, silver halides, especially silver chloride and silver bromide, decompose to yield silver metal and halogen gas (chlorine or bromine gas).

Note:
When you burn a fuel, it produces heat. The total amount of heat produced when a fuel is burned when there is complete combustion with oxygen is referred to as heat of combustion. Automobile fuels such as diesel, as well as the hot engine of a race car or a school bus, are sources of heat energy.