Question

Calculate the actual mass of a molecule of oxygen.

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 Avagadro'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 of ${\mathrm{CO}}_2$ has mass

$=\frac{32}{6.023\times {10}^{23}}$

$=5.314\times {10}^{-23}g$

Actual mass of oxygen molecule = $5.314\times {10}^{-23}$.