Question

What is the equivalent mass of nitrogen in $N{H_3}$ for following reactions
${N_2} + 3{H_2}$ gives $2N{H_3}$ ?

Answer 1

The molecular weight of the solute divided by the valence of the solute gives the equivalent weight of a solution. In an acid-base analysis, such as titration, equivalent weight is used to determine the mass of a chemical that reacts with one atom of hydrogen.
Equivalent mass of $N = \dfrac{{Molar{\text{ mass}}}}{{{n_f}}}$
${n_f} =$ Valency.

Complete answer:
The given reaction is:
${N_2} + 3{H_2} \to 2N{H_3}$
Here the oxidation state of $N$ in ${N_2}$ is $0$ . Whereas, the oxidation state of $N$ in $N{H_3}$ is $- 3$ .
Hence, we can say that $3$ electrons are accepted by $N$ .
Therefore, the valence factor of $N$ is $3$ .
Using the formula of Equivalent mass,
Equivalent mass of $N = \dfrac{{Molar{\text{ mass}}}}{{{n_f}}}$
Substituting the values, we get
Equivalent mass of $N = \dfrac{{14}}{3}$
Equivalent mass of $N \Rightarrow 4.67$

Additional Information:
The given reaction is a combination reaction as nitrogen and hydrogen combine to form ammonia. A combination reaction is a reaction in which one compound is formed by mixing two reactants. A synthesis reaction is another name for a combination reaction. The formation of new bonds is involved in combination reactions, and this process releases a lot of energy in the form of heat. Hence, they are exothermic in nature.

Note:
Atomic weight is the average value of all the masses of a chemical element's naturally occurring isotopes, while valency is the atom's combining capacity. An atomic mass unit is a measure of equal weight.