Question

In the equation, $\mathrm{NaOH}+{\mathrm{HNO}}_3\to {\mathrm{NaNO}}_3+{\mathrm{H}}_2\mathrm{O}$ nitric acid is acting as

• A. an oxidizing agent
• B. an acid
• C. a reducing agent
• D. a dehydrating agent

Answer 1

The correct option is B

an acid

Explanation for correct option:

(B):

• The reaction in which an acid reacts with a base to form salt and water $\left({\mathrm{H}}_2\mathrm{O}\right)$ is known as neutralization reaction.
• The given reaction is as follows:
• $\mathrm{NaOH}\left(\mathrm{aq}\right)+{\mathrm{HNO}}_3\left(\mathrm{aq}\right)\to {\mathrm{NaNO}}_3\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$
• Here, sodium hydroxide $\left(\mathrm{NaOH}\right)$, a base reacts with nitric acid $\left({\mathrm{HNO}}_3\right)$, an acid and forms sodium nitrate $\left({\mathrm{NaNO}}_3\right)$, a salt, and water thus, it is an neutralization reaction.
• And hence, nitric acid $\left({\mathrm{HNO}}_3\right)$ is acting as an acid in the reaction.

Explanation for the incorrect options:

(A) & (C):

• The given reaction is as follows:
• $\mathrm{NaOH}\left(\mathrm{aq}\right)+{\mathrm{HNO}}_3\left(\mathrm{aq}\right)\to {\mathrm{NaNO}}_3\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$
• Since the oxidation state of sodium ($\mathrm{Na}$) is +1 in sodium hydroxide and +1 in sodium nitrate as well,. Similarly, the oxidation state of Nitrogen ($\mathrm{N}$), Hydrogen ($\mathrm{H}$), and Oxygen ($\mathrm{O}$) remains the same, +5, +1, and -2, respectively, on both sides of the reaction. Thus, oxidation and reduction of any participating substance do not occur Thus, none of the compounds is acting as an oxidizing agent or a reducing agent. Thus, the option (A) and (C) are incorrect.

(D):

• The given reaction is as follows:
• $\mathrm{NaOH}\left(\mathrm{aq}\right)+{\mathrm{HNO}}_3\left(\mathrm{aq}\right)\to {\mathrm{NaNO}}_3\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$
• Dehydration agent is the one that eliminates the water molecule from reactant molecules. For example, Concentrated sulfuric acid (${\mathrm{H}}_2{\mathrm{SO}}_4$).
• Since, the elimination of water takes place due to the neutralization of acid and base thus, nitric acid (${\mathrm{HNO}}_3$) is not acting as a dehydrating agent.

Hence, option (B) is correct. Nitric acid is acting as an acid.