Among the metals, Fe, Zn, Pb, Ag and Pt which do not give a metal nitrate on treatment with concentrated HNO_(3)

Among the metals, Fe, Zn, Pb, Ag and Pt which do not give a metal nitr

1.	Among the metals, Fe, Zn, Pb, Ag and Pt which do not give a metal nitrate on treatment with concentrated HNO_(3)
Answer» Fe and Zn Fe and Pt Pb, Ag and Pt Fe, Ag and Pt Solution :When iron is treated with conc. `HNO_(3)`, it BECOMES PASSIVE DUE to the formation of a protective layer of `FeO.Fe_(2)O_(3)` on its surface. Pt, on the other hand, being a noble metal does not react with conc. `HNO_(3)`.