`Zn` gives `H_(2)` gas with `H_(2)SO_(4)` and `HCl` but not with `HNO_(3)` because

Options

A. Zn acts as an oxidising agent when it reacts with `HNO_3`
B. `HNO_3` is weaker acid than `H_2OSO_4` and HCl
C. In electrochemical series, Zn is above hydrogen
D. `NO^(3)` is reduced in preference to hydronium ion

Answer

D

Explanation

(d) Zinc gives `H_2` gas with dil `H_2SO_4`/HCI but not with `HNO_3`, because in `HNO_3, NO_(3)^(-)`, ion is reduced and give `NH_4NO_3, N_2O, NO` and `NO_2`, (based upon the concentration of `HNO_3`,)
[Zn + underset(nearly 6%)`(2HNO_3)rarr Zn(NO_3)_2 +2H] x 4`
`HNO_3 +8H rarr NH_3 +3H_2O`
`NH_3 + HNO_3 rarr NH_4NO_3`
`4Zn + 10HNO_3 rarr 4Zn(NO_3)_2 + NH_4NO_3,+ 3H_2O`
Zn is on the top position of hydrogen in electrochemical series. So Zn displaces `H_2`, from dilute `H_2SO_4`, and HCI with liberation of `H_2`.
`Zn+H_2SO_4 rarr ZnSO_4 + H_2`