MgO+2HCl=>MgCl2+2H2OMgO+2H+2Cl=>Mg+2Cl+2H2OMgO+2H=>Mg+2H2O2Zn+2H2SO4=>2ZnSO4+H2⬆️2Zn+4H+2SO4=>2Zn+2SO4+2H⬆️4H=>2H⬆️3KOH+H3PO4=>K3Po4+3H2O3K+3OH+3H+PO4=>3K+PO4+3H2O3OH+3H=>3H2OOH+H=>H2OAl+3HNO3=>Al(NO3)3+3HAl+3H+3NO3=>Al+3NO3+3H0=0 реакция не проходит