Question

Ammonium chloride dissolves in water with the absorption of heat. Which of the following is true?
A. The solubility of ammonium chloride decreases with increases in temperature.
B. The solubility of ammonium chloride increases with increase in temperature.
C. At higher temperature, ammonium chloride in solution exists as ammonia and hydrochloric acid.
D. At lower temperature, ammonium chloride in solution is present in the molecular form.

Answer 1

Hint: We know that the solubility is defined by the higher amount of solute dissolved in any given aqueous solvent. The solubility generally is affected by the temperature factor.

Complete step by step answer:
As we know that there are two types of reactions one is endothermic and other is exothermic based upon the amount of energy released or amount of energy consumed to form or break the new bond in formation of new compounds from the reactants.
Endothermic reactions are the one which consume energy during the reaction and the new product is formed.
Exothermic reaction is the reaction in which the energy is released in the form of heat energy where the product form will convert the wall of the vessel hot in which the reaction is carried out.
As we all know, the ammonium chloride is one of the inorganic compounds. Generally, ammonium chloride is neutral salt, but the solution of ammonium chloride is mildly acidic in nature. It has white crystalline salt, and it usually easily dissolves in water.
The reaction of ammonium chloride and water is shown below.
${\rm{N}}{{\rm{H}}_{\rm{4}}}{\rm{Cl}} + {{\rm{H}}_{\rm{2}}}{\rm{O}} \to {\rm{N}}{{\rm{H}}_{\rm{4}}}{\rm{OH}} + {\rm{HCl}}$
When ammonium chloride dissolves in water, the absorption of heat occurs shows the reaction is an endothermic reaction. So, in the endothermic reaction, when the temperature increases, the value of the equilibrium constant also increases. Thus, the solubility of ammonium chloride increases when the temperature of the reaction increases.
Therefore, the correct option for this question is B.
Note:
Generally, in the endothermic reaction, the absorption of heat takes place. In this reaction, the reactant of the chemical reaction absorbs the heat from outer surroundings and forms a product. The temperature of the endothermic reaction usually is lower than the surroundings.