Question

Find the salt formed when sodium hydroxide reacts with hydrochloric acid:
(A) $ {\text{NaCl}} $
(B) $ {\text{NO}} $
(C) $ {\text{HCl}} $
(D) $ {\text{Fe}}{\left( {{\text{OH}}} \right)_{\text{3}}} $

Answer 1

Hint :(1) Acid-base reactions involve chemical reactions between acids and bases.
(2) These are neutralization reactions and the products formed are salt and water.

Complete Step By Step Answer:
The given reactants are sodium hydroxide $ \left( {{\text{NaOH}}} \right) $ and hydrochloric acid $ \left( {{\text{HCl}}} \right) $ . We need to find out the salt which is formed when sodium hydroxide $ \left( {{\text{NaOH}}} \right) $ and hydrochloric acid $ \left( {{\text{HCl}}} \right) $ reacts with each other.
It has been observed that when an acid undergoes reaction with a base or an alkali, salt and water is produced. The salt which is produced depends upon which base and which acid is undergoing reaction. The general reaction of neutralization between an acid and a base is given by:
 $ {\text{acid + alkali}} \to {\text{salt + water}} $
In the given question, sodium hydroxide $ \left( {{\text{NaOH}}} \right) $ is a base because it contains hydroxide ions $ \left( {{\text{O}}{{\text{H}}^{\text{ - }}}} \right) $ whereas hydrochloric acid $ \left( {{\text{HCl}}} \right) $ is an acid as it liberates hydrogen ions $ \left( {{{\text{H}}^{\text{ + }}}} \right) $ ions in aqueous solution. So, the reaction between sodium hydroxide $ \left( {{\text{NaOH}}} \right) $ and hydrochloric acid $ \left( {{\text{HCl}}} \right) $ can be written as:
 $ {\text{NaOH + HCl}} \to {\text{NaCl + }}{{\text{H}}_{\text{2}}}{\text{O}} $
So, the salt formed when sodium hydroxide $ \left( {{\text{NaOH}}} \right) $ and hydrochloric acid $ \left( {{\text{HCl}}} \right) $ react is sodium chloride $ \left( {{\text{NaCl}}} \right) $ . So, the salt formed is not $ {\text{NO}} $ or $ {\text{HCl}} $ or $ {\text{Fe}}{\left( {{\text{OH}}} \right)_{\text{3}}} $ . Thus, option (B), option (C) and option (D) are not correct.
So, the correct option is (A).

Note :
The reaction between a strong acid like hydrochloric acid $ \left( {{\text{HCl}}} \right) $ with a strong base like sodium hydroxide $ \left( {{\text{NaOH}}} \right) $ is essentially a quantitative reaction:
 $ {\text{NaOH}}\left( {{\text{aq}}} \right){\text{ + HCl}}\left( {{\text{aq}}} \right) \to {\text{NaCl}}\left( {{\text{aq}}} \right){\text{ + }}{{\text{H}}_{\text{2}}}{\text{O}}\left( {\text{l}} \right) $ .
The neutralization reaction is:
 $ {{\text{H}}^{\text{ + }}}{\text{ + O}}{{\text{H}}^{\text{ - }}} \to {{\text{H}}_{\text{2}}}{\text{O}} $
This neutralization reaction doesn’t involve the sodium and chloride ions. So, both the sodium ion and the chloride ion are spectators in this neutralization reaction.