Question

A $5$ molar solution of ${H_2}S{O_4}$ is diluted from $1L$ to $10L$ . What is the normality of the solution?
(A) $0.25N$
(B) $1N$
(C) $2N$
(D) $7N$

Answer 1

We can solve this problem by using the normality equation. Normality is used to measure the concentration of a solution. It is abbreviated as ‘N’ and it is referred to as the equivalent concentration of a solution. It is mainly used as a measure of reactive species in a solution and during titration reactions or particularly in situations involving acid-base chemistry.

Complete step-by-step solution: So as we know the normality equation is given by.
${N_1}{V_1} = {N_2}{V_2}$
Since normality, ${N_1}$ is not directly given, the equation to find ${N_1}$ is given by
${N_1} = Molarity \times basicity$
The value of molarity is $5molar$and basicity is basically the number of ionizable hydrogen ions present in one molecule of an acid. For sulfuric acid its $2$ since two ionizable hydrogen ions are present in ${H_2}S{O_4}$
Therefore,
${N_1} = 5 \times 2$
${N_1} = 10N$
Since the values for ${V_1}$ and ${V_2}$ is given in the question we can substitute them.
${V_1} = 1L$
${V_2} = 10L$
Hence, by substituting these values in the normality equation we get,
$10 \times 1 = {N_2} \times 10$
${N_2} = \frac{{10 \times 1}}{{10}}$
${N_2} = 1N$

Additional information: Normality is used mainly in three situations:
a.To determine the concentrations in acid-base chemistry.
b.Used in precipitation reactions to measure the number of ions which are likely to precipitate in a given reaction
c.It is used in redox reactions to find the number of electrons which a reducing or an oxidizing agent can donate or accept.

Hence the correct option is (B).

Note: Normality is a way of expressing the concentration of solute in the solution which means it is the equivalent concentration of a solution. It depends on the chemical reaction and on temperature too. It is the reactive capacity of the solution and it is called equivalent concentration. This formula is more commonly used in acid-base reactions and redox reactions.