Question

Calculate the weight of ${10}^{22}$ atoms of carbon.

[ $\mathrm{C}=12$, Avogadro's No. $=6\times {10}^{23}$].

Answer 1

Step 1: Molar mass of carbon $=12g$

Avogadro number $=6\times {10}^{23}$

Step 2: $12g$of carbon contains $6\times {10}^{23}$ atoms

$1$ atom of carbon weigh $=\frac{12}{6\times {10}^{23}}$

${10}^{22}$ atoms of carbon weigh $=\frac{12}{6\times {10}^{23}}\times {10}^{22}$

$=2\times {10}^{-1}$

$=0.2g$

Therefore, weight of ${10}^{22}$ atoms of carbon $=0.2g$.