Question

The mass of one atom of an element is $6.66\times {10}^{-23}g$. The number of gram atoms in $0.320$ $kg$ of the element is :

Answer 1

One gram atom has $N_o$ atoms $=6.02\times {10}^{23}$ atoms.
If the atomic mass $=A$
Then, the mass of one atom $=\frac{A}{N_o}=6.66\times {10}^{-23}g$.
$\frac{A}{N_o}=6.66\times {10}^{-23}$
$\therefore A=6.66\times {10}^{-23}\times 6.02\times {10}^{23}$$=40$ $g$ $mo{l}^{-1}$
Number of gram atoms (moles) in $0.320$ $kg$ are $\frac{0.320\times 1000}{40}=8$.