Question

Molarity of \[{\text{0}}{\text{.2N}}\] \[{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_4}\] is:
A.\[{\text{0}}{\text{.2}}\]
B.\[{\text{0}}{\text{.4}}\]
C.\[{\text{0}}{\text{.6}}\]
D.\[{\text{0}}{\text{.1}}\]

Answer 1

Hint: We must have to remember that the chemical formula of sulphuric acid is \[{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_4}\]. In chemistry, the concentration of the solution is very important. The strength of the solution is very important for inhale solution and medicinal chemistry. There are different ways of representation in the concentration of solutions. There are molality, molarity, normality formality, mole fraction, mass percentage, volume percentage, mass by volume and parts per million.
Formula used:
The molarity of the solution depends on the number moles of the solute and the volume of the solution in litre. The molarity of the solution is equal to the ratio of the number of moles of the solute to the volume of the solution in litre. The symbol of molarity is M.
\[{\text{Molarity = }}\dfrac{{{\text{number of moles of the solute}}}}{{{\text{volume of the solution litre}}}}\]
The normality of the solution depends on the number of the gram equivalents of solute and the volume of the solution in litre. The normality of the solution is equal to the ratio of the number of the gram equivalent of the solute to the volume of the solution in litre. The symbol of normality is N.
\[{\text{Normality = }}\dfrac{{{\text{number of gram equivalent of the solute}}}}{{{\text{volume of the solution litre}}}}\]
The gram equivalent of the acid is dependent on the molecular mass of the acid divided by the basicity of the acid. The basicity of the acid is nothing but the number of hydrogen ion able to donate the acid in aqueous medium. The gram equivalent of the acid is equal to the ratio of the molecular mass of the acid to the basicity of the acid.

Complete answer:
As we know that the basicity of the sulphuric acid is one. Because, only two hydrogen atoms.
The molecular weight of the sulphuric acid is \[{\text{98g}}\].
The basicity of sulphuric acid is \[2\].
The gram equivalent of the sulphuric acid is,
\[ = \dfrac{{98}}{2}\]
On simplification we get,
\[ = 49\]
Given normality of the sulphuric acid is \[{\text{0}}{\text{.2N}}\]
We compare the normality and molarity of the solution,
\[{\text{Molarity = Normality}}\]
\[\dfrac{{{\text{number of moles of the solute}}}}{{{\text{volume of the solution litre}}}}{\text{ = }}\dfrac{{{\text{number of gram equivalent of the solute}}}}{{{\text{volume of the solution litre}}}}\]
Both denominators are equal and cancel each other.
Number of moles we consider as one,
Hence,
\[{\text{Molarity = }}\dfrac{{{\text{Normality}}}}{2}\]
These two depend on the basicity of the acid.
\[ = \dfrac{{0.2}}{2}\]
On division we get,
\[ = 0.1\]
Molarity of \[{\text{0}}{\text{.2N}}\] \[{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_4}\] is \[{\text{0}}{\text{.1M}}\].

Note:
We have to remember that in the acid base concept the hydrogen ion is very important. The acids are proton or hydrogen ion donors. The bases are hydrogen ion or proton acceptor in the reaction. The basicity of the acid and the acidity of the base is dependent on the hydrogen ion in the molecule. The molecular weight of the molecule is the sum of the atomic weight of the atoms in the molecule.