Number of moles of H2=21=0.5 Number of molecules of H2=0.5 NA. (1) Number of moles of N2=2814=0.5 Number of molecules of N2=0.5 NA (2) Number of moles of H2O=1818=1 Number of molecules of H2O=1×NA=NA (3) Number of moles of CO=2816=74 Number of molecules of CO=74 NA (4) Number of moles of N2=2828=1 Number of molecules of N2=1×NA=NA