Question

In what way dilute nitric acid is different from other acid when reacted with metals, as it is generally considered a typical acid except for its reaction with metals:
A.It acts as a reducing agent and hydrogen gas is liberated.
B.It acts as an oxidizing agent and hydrogen gas is liberated.
C.It acts as an oxidizing agent and NO gas and water are formed.
D.It acts as a reducing agent and NO and water are formed.

Answer 1

Nitric acid reacts with most metals, but the details depend on the concentration of the acid and the nature of the metal. Dilute nitric acid behaves as a typical acid in its reaction with most metals. Magnesium, manganese, and zinc liberate Hydrogen.

Complete step by step answer:
-NITRIC ACID is a strong acid that undergoes complete dissociation. So it is considered a typical Acid .But it shows exceptional behavior in reaction with a metal. While other acids react with Metals to form a corresponding metal salt and Releasing Hydrogen gas, Nitric Acid doesn't react with Metals.
-Nitric acid is a strong oxidizing agent, thus when it reacts with metal this acid even oxidizes hydrogen produced to water and itself is reduced to NO gas.
Hence the correct option is (C).

Note:
Nitric acid can oxidize non-active metals such as copper and silver. With these non-active or less electropositive metals the products depend on temperature and the acid concentration. For example, copper reacts with dilute nitric acid at ambient temperatures with a 3:8 stoichiometry. The nitric oxide produced may react with atmospheric oxygen to give nitrogen dioxide. With more concentrated nitric acid, nitrogen dioxide is produced directly in a reaction with 1:4 stoichiometry. Upon reaction with nitric acid, most metals give the corresponding nitrates. Some metalloids and metals give the oxides; for instance, Sn, As, Sb, and Ti get oxidized.