44gCO2
8gH2
64gSO2
48gO3
The number of moles can be calculated from the ratio of the mass to the molar mass. Maximum number of moles will correspond to the maximum number of molecules.
Moles of CO2 = 44/44 = 1 mol
Moles of H2 = 8/2 = 4 mol
Moles of SO2 = 64/64 = 1 mol
Moles of O3 = 48/48 = 1 mol
Since 1 mole of any substance contains Avogadro's number of molecules (6.022 x 10^23), the substance with the maximum number of moles will have the maximum number of molecules. Therefore, 8g of H2 has the maximum number of molecules.