Răspuns:
a) Mr CH4= 1·12+4·1=12+4=16
MrNH3 = 1·14+3·1=14+3=17
MrH2O=2·1+1·16=2+16=18
MrHCl=1·1+1·35,5=1+35,5=36,5
b) MrCO2=1·12+2·16=12+32=44
MrNO2=1·14+2·16=14+32=46
MrN2O5=2·14+5·16=28+80=108
MrNO=1·14+1·16=30
c) MrSO2=1·32+2·16=32+32=64
MrSO3=1·32+3·16=32+48=40
MrSIO2=1·32+1·127+2·16=31+127+32=191
MrP2O5=2·31+5·16=62+80=142
