1.0 g of $\mathrm{H}_2$ has same number of molecules as in:
1.0 g of $\mathrm{H}_2$ has same number of molecules as in:
14 g of $\mathrm{N}_2$
18 g of $\mathrm{H}_2 \mathrm{O}$
16 g of CO
28 g of $\mathrm{N}_2$
Solution
Number of moles of $\mathrm{H}_2=\frac{1}{2}=0.5$
Number of molecules of $\mathrm{H}_2=0.5 \mathrm{~N}_{\mathrm{A}}$.
(1) Number of moles of $\mathrm{N}_2=\frac{14}{28}=0.5$
Number of molecules of $\mathrm{N}_2=0.5 \mathrm{~N}_{\mathrm{A}}$
(2) Number of moles of $\mathrm{H}_2 \mathrm{O}=\frac{18}{18}=1$
Number of molecules of $\mathrm{H}_2 \mathrm{O}=1 \times \mathrm{N}_{\mathrm{A}}=\mathrm{N}_{\mathrm{A}}$
(3) Number of moles of $\mathrm{CO}=\frac{16}{28}=\frac{4}{7}$
Number of molecules of $\mathrm{CO}=\frac{4}{7} \mathrm{~N}_{\mathrm{A}}$
(4) Number of moles of $\mathrm{N}_2=\frac{28}{28}=1$
Number of molecules of $\mathrm{N}_2=1 \times \mathrm{N}_{\mathrm{A}}=\mathrm{N}_{\mathrm{A}}$