Chapter 2 Atoms, Molecules, and Ions - 2-9 Atoms, Molecules, and the Mole - Review & Check for Section 2-9 - Page 83: 2

B

Molar masses: $O_2: 31.998\ g/mol,\ H_2:2.016\ g/mol,\ F_2: 37.996\ g/mol,\ N_2: 28.014\ g/mol$ Number of moles: $24\ g\ of\ O_2$: $0.75\ mol$ $4.0\ g\ of\ H_2$: $2.0\ mol$ $19\ g\ of\ F_2$: $0.50\ mol$ $28\ g\ of\ N_2$: $1.0\ mol$ Therefore, the bigger number of molecules is 4.0 g of hydrogen.