Question

Write a balanced chemical equation when sodium reacts with a hydrochloric acid to produce sodium chloride solution and water.
(A) $NaOH\left( {aq} \right) + HCl\left( {aq} \right) \to NaCl\left( {aq} \right) + {H_2}O\left( l \right)$
(B) $2NaOH\left( {aq} \right) + HCl\left( {aq} \right) \to 2NaCl\left( {aq} \right) + {H_2}O\left( l \right)$
(C) $NaOH\left( {aq} \right) + 2HCl\left( {aq} \right) \to NaCl\left( {aq} \right) + 2{H_2}O\left( l \right)$
(D) $NaCl\left( {aq} \right) + HCl\left( {aq} \right) \to NaCl\left( {aq} \right) + {H_2}O\left( l \right)$

Answer 1

Hint: According to Arrhenius acid$ - $base theory. Acids are substances that dissociates in water to yield electrically charged atoms or molecules called ions, one of which is a hydrogen ion $\left( {{H^ + }} \right)$ and the base ionize in water to yield $O{H^ - }$ ions (hydroxide ions).

Complete step by step answer:
We know that,
$HCl\left( g \right)\xrightarrow{{{H_2}O}}{H^ + }\left( {aq} \right) + C{l^ - }\left( {aq} \right)$
As $HCl$ gives ${H^ + }$ in water, it is an acid (Arrhenius theory)
$HCl$ is an Arrhenius acid and $NaOH$ is Arrhenius base, hence it comes out to be a neutralization reaction.
Neutralization reaction:
Acid $ + $Base $ \to $ Salt $ + $ Water
As this reaction is taking place in water. Hence, the physical state will be aqueous.
So, the net equation will be:
$NaOH\left( {aq} \right) + HCl\left( {aq} \right) \to NaCl\left( {aq} \right) + {H_2}O\left( l \right)$

So, the correct answer is “Option A”.

Additional Information:
A neutralization is a type of reaction (double displacement reaction). A salt is the product on acid$ - $base reaction. It is a reaction of an acid and a base
 Acid $ + $ Base $ \to $ Salt $ + $ Water


Note:
Arrhenius theory is limited as it can only describe acid$ - $base chemistry in aqueous solutions. Similar reactions can also occur in non-aqueous solvents , however as well as between molecules in the gas phase.