2AL+3S=AL2S3 N2+3H2=2NH3 Fe2O3+2AL=AL2O3+2Fe
PbO2=Pb+O2 Ca(OH)2+2HNO3=Ca(NO3)2+2H2O 2 Fe(OH)3+3H2SO4=Fe2(SO4)3=6H2O
m=80 X
H2SO4+2NaOH=Na2SO4=2H2O
m=98 m=142
m(NaOH)=m*w=200*0.4=80 X=80*142\98=
или n(H2SO)4=m\M n=80\98=0,82 моль m(Na2SO4)=n*M m=0,82*142=116