Question

When magnesium oxide reacts with $HCl$, it gives
A.) ${H_2}O$
B.) ${O_2}$
C.) salt and water
D.) $MgC{l_2}$

Answer 1

Hint: In this question, magnesium oxide can be written as $MgO$ and when magnesium oxide reacts with the hydrogen chloride that is $HCl$ then in product magnesium chloride and water is produced.

Complete step by step answer:
Here, magnesium oxide is a simple basic oxide. Magnesium oxide is not so strongly basic oxide because in magnesium oxide, oxide ions are not so free. In magnesium oxide, the magnesium ion has $ + 2$ charge on it that is $M{g^{2 + }}$ and oxide ion has $ - 2$ charge on it that is ${O^{2 - }}$. Therefore, the chemical formula of magnesium chloride can be written as $MgO$.
When a dilute acid reacts with a base or alkali medium then the salt and water is produced in this reaction. This happens because the acidity and basicity of the acid and base respectively neutralize each other. This process is known as neutralization reaction. Here, a salt is that chemical compound which is composed of a related number of anions and cations and they are electrically neutral products. The same neutralization reaction happens when magnesium oxide reacts with the hydrochloric acid.
As we know that magnesium oxide is a base or alkali and hydrogen is acidic in nature. Therefore, when magnesium oxide ($MgO$) reacts with hydrochloric acid ($HCl$) then magnesium chloride that is $MgC{l_2}$ and water (${H_2}O$) is formed. Here, $MgC{l_2}$ is a salt . This reaction can be represented as:
$MgO + 2HCl \to MgC{l_2} + {H_2}O$

So the correct answer is option C

Note: Remember that if an acid reacts with an alkali medium then the product obtained will include a salt and water. This happens because the acidity and basicity of the acid and base respectively neutralize each other as we saw in the reaction of magnesium oxide and hydrogen chloride.