Question

When copper is heated with conc. `HNO_(3)` it produces?
A. `Cu(NO_(3))_(2)` and NO
B. `Cu(NO_(3))_(2)`, `N_(2)O`
C. `Cu(NO_(3))_(2)` and `N_(2)O`
D. `Cu(NO_(3))_(2)` and `NO_(2)`

Answer 1

Correct Answer - D
Nitric acid acts as an oxidising agent while reacting with copper. When dil `HNO_(3)` reacts, reaction proceeds as:
`3Cu+8HNO_(3)(dil). To 3Cu(NO_(3))_(2)+2NO+4H_(2)O`.
and when conc. `HNO_(3)` is used, reaction proceeds as and `Cu+4HNO_(3) ("conc") to Cu(NO_(3))_(2)+2NO+4H_(2)O` and when conc. `HNO_(3)` is used, reactio proceeds as
`Cu+4HNO_(3)("conc") to Cu(NO_(3))_(2) + 2NO_(2)+2H_(2)O`