Question

$ 2.5\, cm^3 $ of $ 0.2\, M\, H_2SO_4 $ solution is diluted to $ 0.5\, dm^3 $ . Find normality of the diluted solution.

• A. $ 0.2 \,N $
• B. $ 0.02 \,N $
• C. $ 0.002 \,N $
• D. $ 0.04 \,N $

Answer 1

Answer: (C)

Given,

volume of $H _{2} SO _{4}$ before dilution, $V_{1}=2.5 \,cm ^{3}$

$=2.5 \times 10^{-3} \,dm ^{3}$

volume of $H _{2} SO _{4}$ after dilution, $V_{2}=0.5 \,dm ^{3}$

Concentration of $H _{2} SO _{4}$ before dilution $=0.2 \,M$

$=0.4\, N [\because 1 \, N =2 \,M ]$

Concentration (normality) of $H _{2} SO _{4}$ after dilution, $N_{2}=$ ?

Normality equation is

$\underset{\text{(before dilution) }}{N_{1}V_{1}} = \underset{\text{(after dilution) }}{N_{2}V_{2}}$

$ 2.5 \times 10^{-3} \times 0.4 =N_{2} \times 0.5$

$\therefore N_{2} =\frac{2.5 \times 10^{-3} \times 0.4}{0.5} $

$=2 \times 10^{-3}=0.002 \,N $