Question

$20\, mL$ of $10 \,N\, HCl$ are mixed with $10\, mL$ of $36 \,N\, H _{2} SO _{4}$ and the mixture is made $1 \,L .$ Normality of the mixture will be

• A. 0.56 N
• B. 0.50 N
• C. 0.40 N
• D. 0.35 N

Answer 1

Answer: (A)

For $H C l$
For $ H _{2} SO _{4} $
$V_{1}=20 \,mL$
$V_{2}=10\, mL$
$N_{1}=10 \,N $
$N_{2}=36 \,N$
$\therefore $ Normality of resulting mixture
$(N)=\frac{N_{1} \,V_{1}+N_{2} \,V_{2}}{V_{1}+V_{2}} $
$=\frac{10\, N \times 20+36 \,N \times 10}{20+10} $
$=\frac{200 \,N+360\, N}{30}$
$=\frac{560 \,N}{30}=18.67\, N$
$\therefore $ The mixture is made one litre,
therefore the normality of this solution is
$N_{1}\, V_{1}=N_{2} \,V_{2}$
$\therefore 18.67 \times 30=N_{2} \times 1000$
$N_{2} \frac{18.67 \times 30}{1000}=0.56\, N$