2NH3 + 2KMnO4 -> N2 + 2MnO2 + 2KOH + 2H2O
2N(-3) -6e -> N2(0) 1 ок-ие
в-ль
Mn(+7) +3e -> Mn(+4) 2 в-ие
ок-ль
2H2O = 2H2 + O2
m(H2O) = 1.8 g
M(H2O) = 16 + 2 * 1 = 18 g/mol
n(H2O) =m/M = 1.8 / 18 = 0.1 mol
n(O2) = n(H2O) / 2 = 0.05 mol
V(O2) = n*Vm = 0.05 * 22.4 = 1.12 l
NaOH+HCl=NaCl+H2O
FeCl3+3NaOH=3NaCl+Fe(OH)3
2Fe(OH)3+3H2SO4=Fe2(SO4)3+6H2O
Ню (ZnO)=40,5/81=0,5
m(Zn)=0/5*63=31,5