Illustrate how copper metal can give different product on reaction with `HNO_3`.

Explanation

On heating with dil. `HNO_(3)`, copper gives copper nitrate and nitric oxide. `3 Cu+8 HNO_(3) (dil) rarr 3 Cu(NO_(3))_(2), + 4 H_(2)0 +2 NO`
Nitric oxide With conc. `HNO_(3)`, instead of NO, `NO_(2)`, is evolved.
` Cu +4 HNO_(3) (con) rarr 3Cu(NO_(3) )_(2) + 2 H_(2)0 +2NO_(2)`, With Conc `HNO_(3)` ,insted of NO,` NO_(2)` is evolved.
`Cu + 4HNO_(3)(conc) rarr 3Cu(NO_(3))_(2) + 2H_(2)O + 2NO_(2)`