Question

Write balanced equation for silver chloride reacts with ammonium hydroxide:
A. \[AgCl + N{H_4}OH \to [Ag{(N{H_3})_2}] + 2{H_2}O\]
B. \[AgCl + 2N{H_4}OH \to [Ag(N{H_3})] + 2{H_2}O\]
C. \[AgCl + 2N{H_4}OH \to [Ag{(N{H_3})_2}] + 2{H_2}O\]
D. \[AgCl + 2N{H_4}OH \to [Ag{(N{H_3})_2}] + {H_2}O\]

Answer 1

Hint: To balance the reaction, we can use the law of conservation of mass. Hit and trial method is used to balance the number of atoms on both, left and right side of the reaction. The mass of products in a chemical reaction must be equal to the mass of reactants.

Complete step by step answer:
-According to the law of conservation of mass, in an isolated system, mass is neither created nor destroyed by any chemical or physical transformations.
-A chemical equation represents the substances that are involved in a chemical reaction i.e. reactants and products. The balanced chemical equation is the one which has the same number of atoms on both sides of a reaction.
-Silver chloride reacts with ammonium hydroxide and results in formation of diamine silver salt and water molecules. This shows us that silver chloride is sparingly soluble in ammonia but can be dissolved in an excess of ammonia solution as per Le Chatelier’s principle.
-Although it has very less solubility product, yet some free silver ions are found in solution which are consumed by excess ammonia because ammonia is a good sigma electron pair donor
-Now we know the reactants used and products formed in this chemical reaction, so we can balance the chemical equation by counting and equalising the number of atoms of each species involved on both the sides of an arrow.
 \[AgCl + 2N{H_4}OH \to [Ag{(N{H_3})_2}] + 2{H_2}O\]

Type of Atom	No. of atoms on left side	No. of atoms on right side
N	2	2
Ag	1	1
O	2	2
H	10	10
Cl	2	2

Hence, the correct option is (C).

Note:
These balancing numbers are called stoichiometric coefficients. It is the number written in front of atoms, ions and molecules in a chemical reaction to balance the number of each element on both the sides. It gives the ratio of moles of reactants and products. It can be a fraction value too.