Find the number of moles of methane in $0.8\text{g}$ of methane.

Step 1: Given information

$0.8\text{g}$ of Methane$\left({\mathrm{CH}}_4\right)$

Step 2: Calculation of molecular weight of ${\mathrm{CH}}_4$

The molecular weight of ${\mathrm{CH}}_4$=$\left(12+1\times 4\right)\text{g}$

$=16\text{g}$

Step 3: Calculation of number of moles of Methane

$16\text{g}$ of Methane contains $1\text{mol}$ of ${\mathrm{CH}}_4$

$0.8\mathrm{g}$ of Methane will contain $\frac{1}{16}\times 0.8=0.05\mathrm{mol}$ of ${\mathrm{CH}}_4$

Hence, the number of moles of Methane in $0.8\text{g}$ Methane is $0.05\text{mol}$.