Question

The weight of $1\times {10}^{22}$ molecules of $CuS{O}_4\cdot 5H_{2}O$ is .......................

Answer 1

Molar mass of $CuS{O}_4\cdot 5H_{2}O$
$=63.5+32+4\times 16+5\times 18=249.5g$
Also, molar mass represents mass of Avogadro number of molecules in gram unit, therefore
$\because$ $6.023\times {10}^{23}$ molecules of $CuS{O}_4\cdot 5H_{2}O$ weigh $249.5g$
$\therefore {10}^{22}$ molecules will weigh $\frac{249.5}{6.023\times {10}^{23}}\times {10}^{22}=4.14g$