Question

How many moles of hydrogen are present in 1 gm of hydrogen?

Answer 1

Molar mass of $H=1g/mole$.

No. of moles= $\frac{givenmass}{molarmass}$

No. of moles in $1g$ of $H=\frac{1g}{1g/mole}=1mole$.
Thus $1$ mole of $H$is present in $1$ g of $H$.