Question

$0.1MHCl$ and $0.2M{H}_{2}S{O}_4$ solutions are mixed in equal volume. This solution is diluted to double the volume. $20ml$ of this diluted solution can neturalise $xml$ of $0.1MNaOH$ solution. Find $x$:

• A. $20ml$
• B. $40ml$
• C. $50ml$
• D. $25ml$

Answer 1

Answer: (D)

$25ml$

$0.1$ $N$ $HCl$, $0.4$ $N$ $H_{2}S{O}_4$

$N_t=\frac{N_1{V}_1+N_2{V}_2}{V_1+V_2}=\frac{0.1\times V+0.4\times V}{V+V}=0.25$

Volume is doubled $\to$ Concentration is halved.

Now, $N_1{V}_1=N_2{V}_2$

$0.125\times 20=x\times 0.1$

$x=25$ $mL$