N2+3H2=2NH3
CO2+Ca(OH)2= CaO+C(OH)4
NH3+N2SO4= 2N2+3H2(SO4)
SiO2+NaOH=Si(OH)4+Na2O
Cu+HNO3=Cu(NO3)+H2
3.01•10*23.N=n•NA=m:M•NA= 22:44•6,02•10"23