Question

Calculate the number of molecules of sulphur $\left(S_8\right)$ present in 16 g of solid sulphur.

Answer 1

1 mole of solid sulphur $\left(S_8\right)$ = 8 X 32 g = 256 g
i.e., 256 g of solid sulphur contains $=6.022\times {10}^{23}$ molecules
Then, 16 g of solid sulphur contains $=\frac{6.022\times {10}^{23}}{256}\times 16$ molecules
$=3.76375\times {10}^{22}$ molecules