Question

(a) Dilute nitric acid is generally considered a typical acid except for its reaction with metals. In what way is dilute nitric acid different from other acids when it reacts with metals?

(b) Write the equation for the reaction of dilute nitric acid and conc. nitric acid with copper.

Answer 1

(a) Dilute acid is generally considered a typical acid except for its reaction with metals
since it does not liberate hydrogen. It is a powerful oxidizing agent and the nascent
oxygen formed oxidizes the hydrogen to water.

(b) (i) With diluted $HN{O}_3$

$3Cu+8HN{O}_3⟶3Cu(N{O}_3{)}_2+4H_{2}O+2NO$

(ii) With conc. $HN{O}_3$

$Cu+4HN{O}_3⟶Cu(N{O}_3{)}_2+2H_{2}O+2N{O}_2$