1) KOH + HNO3 = KNO3 + H2O
K+ + OH- + H+ + NO3- = K+ + NO3- + H2O
OH- + H+ = H2O
2) AgF + NaBr = AgBr↓ + NaF
Ag+ + F- + Na+ + Br- = AgBr↓ + Na+ + F-
Ag+ + Br- = AgBr↓
3) Cu(OH)2 + 2HCl = CuCl2 + 2H2O
Cu(OH)2 + 2H+ + 2Cl- = Cu2+ + 2Cl- + 2H2O
Cu(OH)2 + 2H+ = Cu2+ + 2H2O