Aluminium (Al), lead (Pb) and zinc (Zn) react with NaOH to produce the corresponding metallic salt along with the evolution of hydrogen gas.
Zn produces sodium zincate (Na2ZnO2), Pb produces sodium plumbite (NaPbO2) and Al produces sodium aluminate (NaAlO2).
Zn(s) + 2NaOH(aq) → Na2ZnO2(aq) + H2(g)
Pb(s) + 2NaOH(aq) → Na2PbO2(aq) + H2(g)
2Al(s) + 2NaOH(aq) +2H2O(l)→ 2NaAlO2(aq) + 3H2(g)