Question

Calculate the actual mass of a molecule of NH3.

Answer 1

Step 1: we know that atomic mass and molecular mass is given for one mole of atoms or molecules, so by dividing the mass by Avogadro's number we will find the mass of one atom and one mole molecules.

Step 2:

mass of one atoms of any substance

$=\frac{\mathrm{Atomic}\mathrm{mass}}{\mathrm{Avagadro}\mathrm{number}}$

Step 3 :1 Molecule $N{H}_3$ has mass

$$\begin{gathered} =\frac{17}{6.023\times {10}^{23}} \\ =2.82\times {10}^{-23}g \end{gathered}$$

Mass of ${\mathrm{NH}}_3$ molecule = $2.82\times {10}^{-23}g$