Question

What is the molar mass of ${\text{NH}}_3$?

• A. 17

Answer 1

The correct option is A 17
Molecular mass is equal to the sum of the masses of its constituent atoms.

Atomic mass of nitrogen = 14 u
Atomic mass of hydrogen = 1 u

$\therefore$ Molecular mass of $N{H}_3$
= atomic mass of nitrogen + 3 $\times$ atomic mass of hydrogen
= 14 + (3 $\times$1) = 14+3 = 17 u.