Question

What volume (in mL) of a 45% (v/v) acid solution of a monoprotic strong acid must be mixed with a 20% (v/v) solution of the same acid to produce 800 mL of a 29.875% (v/v) acid solution?

• A. 330
• B. 316
• C. 32
• D. 325

Answer 1

The correct option is B 316

Let the volume of 45% (v/v) acid solution to be mixed be x mL.
Let $C_1,C_2$ and $C_3$ be concentrations and $V_1,V_2$ and $V_3$ their respective volumes. Then,
$C_1{V}_1+C_2{V}_2=C_3{V}_3$
Here, $V_1$ = x mL,$V_2=(800-x)$ mL and $V_3$ =800 mL
45x + 20(800 - x) = 29.875(800)
On solving, we get
x = 316 mL
Hence, 316 mL of 45% (v/v) acid solution of monoprotic strong acid must be mixed with a 20% (v/v) solution of the same acid to produce 800 mL of 29.875% (v/v) acid solution.