a) 2K+2H2O--->2KOH+H2
KH+H2O--->KOH+H2
K2O+H2O--->2KOH
b) CoCl2+2NaOH--->Co(OH)2↓+2NaCl
c) Pb(NO3)2+2KOH--->Pb(OH)2↓+2KNO3
e) 2Na+2H2O--->2NaOH+H2
NaH+H2O--->NaOH+H2
Na2O+H2O--->2NaOH
f) 3KOH+FeBr3--->Fe(OH)3↓+3KBr
g) Ba+2H2O--->Ba(OH)2+H2
BaH2+2H2O--->Ba(OH)2+2H2
BaO+H2O--->Ba(OH)2