Question

The hydride used as refrigerant in ice plants is:

$$A.{\text{ }}N{H_3} \\\ B.{\text{ }}P{H_3} \\\ C.{\text{ }}NC{l_3} \\\ D.{\text{ }}PC{l_3} \\\$$

Answer 1

In order to solve the given problem first we study in brief about the hydrides. How these hydrides formed, along with their chemical composition. Further we will see the basic features required for a compound to be used as a refrigerant and further we will see out of the four options which one has the given features to satisfy as refrigerant and also we will see a brief introduction of the compound used as the refrigerant in ice plants.

Complete step by step answer:
Hydrides refer to compounds and ions in which a smaller electronegative part is covalently bound to hydrogen. The hydride anion is detected very seldom. Hydrogen compounds containing less electronegative elements are known as hydrides. The substance formed is thus known to be a hydride when hydrogen reacts with some other element.
A refrigerant is a material or mixture used in a heat pump and refrigeration cycle, typically a fluid. In most cycles it undergoes phase transitions from a liquid to a gas and back again. For those reasons, many operating fluids have been used. Refrigerants are liquids that have a high latent heat and are converted under minor pressure changes into vapours.
The basic requirement for a compound to act like a refrigerant in high latent heat.
As we know that the liquid ammonia has a very high latent heat of vaporization which is around $5700cal/mol$ . So, ammonia acts as a refrigerant in the ice plant. We know that vaporization of liquid requires external energy and ammonia due to high latent heat of vapourisation absorbs a lot of heat and thus produces the cooling effect in the ice plant.
Hence, the hydride used as refrigerant in ice plants is $N{H_3}$ .
So, the correct answer is “Option A”.

Note: In order to solve such types of problems students must remember the basics required for a compound to act as a refrigerant. Students must know basic features of hydrides as well. If we closely observe the periodic formation of table hydrides, elements of the VA group are not seen and this state is known as the hydride distance. The molecule of hydrogen normally reacts to form hydrides with several elements except noble gases. However, depending on the type of intermolecular force that occurs between the atoms, their molecular masses, temperature and other variables, the properties can differ.