Question

The ratio of molarity and normality of a dibasic acid solution is:
A.$4$
B.$2$
C.$\dfrac{1}{5}$
D.$\dfrac{1}{2}$

Answer 1

We know that to solve this question we should know about dibasic acid. If we want to find an amount of acid in solution, we can use the concept of molarity. Molarity equation will lead us to the answer. The formula here for normality is given by; $Normality=\left( molarity \right)\times \left( equivalent-H \right)$

Complete answer:
At first we will know about the dibasic acid. From the term dibasic acid, we can commonly refer to any substance that can donate two protons or hydrogen $({{H}^{+}})$ ions per molecule in an acid base reaction. Due to this property, the dibasic acid is also known as diprotic acids. A dibasic acid yields two free hydrogen ions in solution for each molecule of acid ionized or in other terms, has two replaceable hydrogen atoms. A simple example of a dibasic acid is sulphuric acid $({{H}_{2}}S{{O}_{4}}).$
$Normality=\left( molarity \right)\times \left( equivalent-H \right)$ here we know that for dibasic acid solution, equivalent−H $=2$
Thus after substituting we get;
$Normality=\left( molarity \right)\times 2$
Taking molarity to L.H.S. we get;
$\dfrac{Normality}{molarity}=2$
We have to find the ratio for molarity and normality, thus taking reciprocal of above equation;
$\Rightarrow \dfrac{molarity}{Normality}=\dfrac{1}{2}$

Hence, option D is correct.

Additional Information:
For a dibasic acid, the normality is twice its molar concentration. In other words, the molar concentration is one half its normality. In general, for an acid, the molarity is equal to the product of normality and basicity. A dibasic acid gives two protons per molecule upon dissociation.

Note:
Remember that in this question we use the concept of both molarity and equivalent weight. There is one important difference we used in this question that is weight and mass. Mass is the amount of matter in something, while weight is the gravitational pull on a mass.