Question

State True or False.
Equivalent mass of $N{{H}_{3}}$ is 17.
A. True
B. False

Answer 1

Hint: All elements combine with each other according to the laws of chemical combination, and the number of parts by which an element combines with 1part by mass of hydrogen, 8 parts by mass of oxygen, or 35.5 parts by mass of chlorine, or one-gram equivalent of any other element, is the value of the equivalent mass of the element.

Complete answer:
Calculating Equivalent Mass:
The formula for the calculation of an element's equivalent mass is given by:
Equivalent mass = $\dfrac{Atomic\,mass}{Valency}$
Let’s discuss how to find equivalent masses of compounds:
1. Equivalent mass of acids.
An acid is a compound which contains one or more hydrogen atoms that can be replaced by a metal. And the number of hydrogen atoms which can be replaced by a metal in an acid gives us the basicity of the compound.
Equivalent mass of an acid = $\dfrac{Molecular\,mass\,of\,acid}{Basicity}$
2. Equivalent mass of bases.
Acidity of an atom is a bit different; it is the number of molecules of a monobasic acid (or an acid with basicity 1) required to completely neutralize one molecule of the base.
The following formula gives the equivalent mass of a base:
Equivalent mass of a base = $\dfrac{Molecular\,mass\,of\,base}{Acidity}$
3. Equivalent Mass of Salts.
The equivalent mass of a salt is defined as the mass of the salt formed when one equivalent of an acid is completely neutralized by one equivalent of a base.
As given in question we have to find Equivalent mass of $N{{H}_{3}}$. $N{{H}_{3}}$ is base,
Hence, Equivalent mass of $N{{H}_{3}}=\dfrac{Molecular\,mass\,of\,N{{H}_{3}}}{Acidity}$
Molecular mass of $N{{H}_{3}}$ = 17
Acidity of $N{{H}_{3}}$ is 1.
Hence, Equivalent mass of
Equivalent mass of $N{{H}_{3}}$ is 17.
Hence, the given statement is true.

Hence, option A is the correct answer.

Note:
It is important to remember that the number of hydrogen atoms which can be replaced by a metal in an acid gives us the basicity of the compound and hence the basicity can be measured.