The weight of a molecule of the compound ${\mathrm{C}}_{60}{\mathrm{H}}_{22}$ is:

Let the mass of the given compound is x. Thus,

$x=\frac{742\times 1}{6.023\times {10}^{23}}$

$=123.19\times {10}^{-23}\mathrm{gm}$

$=1.2319\times {10}^{-24}\mathrm{gm}\approx$$1.24\times {10}^{-21}\mathrm{g}$