Which has the maximum number of molecules among the following ?

Maximum number of moles have maximum number of molecules

∴ calculate number of moles.

$8g {\mathrm{H}}_{2 }\text{moles}=\frac{8}{2}=4 \text{moles}$

$44\mathrm{g} \text{of }{\mathrm{CO}}_2=\frac{44}{44}=1 \mathrm{mol} {\mathrm{CO}}_2$

$64{\mathrm{g} \mathrm{SO}}_2 \text{moles}=\frac{64}{44}=1 \text{moles}$

$48\mathrm{g} \text{of }{\mathrm{O}}_3=\frac{48}{48}=1\mathrm{mol} \text{of }{\mathrm{O}}_3$