Question

Find the mass (in kilogram) of an ammonia molecule $N{H}_3$

Answer 1

Mass of one mole, that is $6.022X{10}^{23}$ molecules of ammonia is $17g$. Thus, mass of one molecule is $m=\frac{17}{6.022X{10}^{23}}g=2.82X{10}^{-26}Kg$

Answer is $2.82X{10}^{-26}Kg$