1. K2O+2HCl--->2KCl+H2O
2. K2O+H2O--->2KOH
3. KOH+HCl--->KCl+H2O
4. 2K+2H2O--->2KOH+H2
5. 2KOH+H2SO4--->K2SO4+2H2O
6. 2K+H2SO4--->K2SO4+H2