Question

In this reaction, equivalent weight ${H_2}S{O_4} + NaOH \to NaHS{O_4} + {H_2}O$
A.$98$
B.$49$
C.$40$
D.None of the above

Answer 1

This question gives the knowledge about the equivalent weight. Equivalent weight is defined as the weight of a chemical compound having one equivalent of hydroxide for base or one equivalent of a proton for acid.

Formula used:
The formula used to determine the equivalent weight is as follows:
$E = \dfrac{M}{n}$
Where $E$ is the equivalent weight, $M$ is the molecular weight and $n$ is the n-factor.

Complete step by step answer:
Equivalent weight is defined as the weight of a chemical compound having one equivalent of hydroxide for base or one equivalent of a proton for acid. Molecular weight and equivalent weight are two different entities. Molecular formula is important for determining both of them. The molecular formula is the representation of chemical compounds. It comprises the chemical symbols for the elements tailed by the numeric subscripts labelling the atoms of each element present in a molecule.
Consider the reaction,
${H_2}S{O_4} + NaOH \to NaHS{O_4} + {H_2}O$
In the above reaction, the acid is ${H_2}S{O_4}$.
Now, we will determine the equivalent weight of this acid using formula as follows:
$\Rightarrow E = \dfrac{M}{n}$
The n-factor for the acid ${H_2}S{O_4}$ is $1$ because here only one replaceable hydrogen is present.
Substitute molecular formula of sulphuric acid as $98$ and n-factor as $1$ in the above equation as follows:
$\Rightarrow E = \dfrac{{98}}{1}$
Therefore, the equivalent weight of acid ${H_2}S{O_4}$ is $98$.

Hence, option A is correct.

Note:
Always remember the equivalent weight of different chemical compounds based on their acidity or basicity. Molecular weight and equivalent weight are two different entities. It is the weight of a chemical compound having one equivalent of hydroxide for base or one equivalent of a proton for acid. Equivalent weight is also known as gram equivalent.