Al+6HNO3=Al(NO3)3+3NO2+3H2O
3Cu+8HNO3=3Cu(NO3)2+2NO+4H2O
Na+2HNO3=NaNO3+H2O+NO2
2Al(OH)3(осадок)+3H2SO4=Al2(SO4)3+6H2O
2Al(OH)3+6H+ + 3SO4 2- = 2Al3+ + 3SO4 2- + 6H2O
2Al(OH)3=2Al3+ + 6H2O
K2O+2HCl=2KCl+H2O
K2O+2H+ + 2Cl- = 2K+ 2Cl - + H2O
K2O+2H+=2K+ + H2O
PbSO4+2KI=K2SO4+PbI2(осадок)
Pb 2+ + SO4 2- + 2K+ +2I- = 2K+ + SO4 2- + PbI2
Pb2+ + 2I - = PbI2
2KOH+H2S=K2S+2H2O , 2K+2OH+2H+S=2K+S+2H2O ответ:2