Question

A 1-liter solution containing 490g of sulphuric acid is diluted to 10 liters with water. What is the normality of the resulting solution?
A.0.5N
B.1.0N
C.5.0N
D.10.0N

Answer 1

Hint : We can use the neutralization law equation, ${N_1}{V_1} = {N_2}{V_2}$to determine the normality of the resulting sulphuric acid solution.

Complete step by step solution :
We can use the neutralization law equation to solve the given question.
${N_1}{V_1} = {N_2}{V_2}$
Where,
N is normality and V is volume.
Normality is the ratio that relates the amount of solute to the total volume of the solution. We can define it as the number of equivalents per liter of solution.
The number of gram equivalents of solute dissolved per Liter of the solution is known as the normality of the solution.
Equivalent mass of ${H_2}S{O_4}$= $\dfrac{{{\text{molecular mass of }}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}}}{{{\text{basicity of }}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}}}$ = $\dfrac{{98gm}}{2}$ = $49{\text{ }}gm$
Normality = number of equivalents / 1 L of solution
Normality of ${H_2}S{O_4}$ = $\dfrac{{{\text{given mass }}}}{{{\text{equivalent mass }} \times {\text{ volume of solution in litre }}}}$
Therefore, Normality of ${H_2}S{O_4}$= $\dfrac{{490}}{{49 \times 1L}}$ = 10 N
So, Normality of given ${H_2}S{O_4}$ is 10N
According to the neutralization law,
${N_1}{V_1} = {N_2}{V_2}$
where,
N1= Normality of H2SO4= 10 N
V1 = volume of NaOH solution = 1 L
N2 = Normality of second solution = ? N
V2 = volume of second solution = 10L
Putting these above values in neutralization equation, we get
$10N{\text{ }} \times 1L{\text{ }} = {\text{ }}{N_2} \times {\text{ }}10{\text{ }}L$
∴ ${N_2} = \dfrac{{10N{\text{ }} \times 1L}}{{10L}}$
∴ ${N_2} = \;1{\text{ }}N$
Therefore, the normality of the resultant solution will be 1N.
Option B is the correct answer.

Note : The determination of normality is useful in precipitation reactions. Therefore, we can measure the number of ions which are likely to precipitate in a specific reaction. And also we can use normality in redox reactions to determine the number of electrons that a reducing or an oxidizing agent can donate or accept.