Question

$20\%$(w/w) $HCl$ solution has density $1.25$ g/ml is given. Volume of this solution required to prepare $200$ ml of $0.2$M $HCl$ is:

• A. $2.85$ml
• B. $6.5$ml
• C. $5.84$ml
• D. $2.5$ml

Answer 1

Answer: (C)

$5.84$ml

$20\%$ (w/w) $HCl$ is $20g$ $HCl$ is $100g$ solution.

Volume of solution $=\frac{100}{1.25}=80ml$

Molarity of this solution $=M_1=\frac{20\times 1000}{36.5\times 80}=6.85M$

$\because M_1{V}_1=M_2{V}_2$

$V_1=\frac{0.2\times 200}{6.85}=5.84ml$