Zn+2 dissolves in excess of NaOH due to the formation of
Soluble Zn(OH)2
Soluble Na2Zn(OH)4
Soluble NaZn(OH)3
ZnO
Zn+2+2NaOH→Na2ZnO2+H2Na2ZnO2+2H2O→Na2Zn(OH)4