Question

Solution A containing $0.5N$ $HCl$ and solution B containing $0.1N$ $HCl$ are mixed to form $0.2N$ $HCl$ solution. Which of the following could be the possible volumes of solution A and B respectively?

• A. $0.5$ L of A and $1.5$ L of B
• B. $1.5$ L of A and $0.5$ L of B
• C. $1$ L of A and $1$ L of B
• D. $0.75$ L of A and $1.25$ L of B

Answer 1

Answer: (A)

$0.5$ L of A and $1.5$ L of B

$(N\times V{)}_{initial}=(N\times V{)}_{final}$

$⟹(N_A\times V_A+N_B\times V_B)=(N_{A+B}\times V_{A+B})$

$⟹0.5\times V_A+0.1\times V_B=V_{A+B}\times 0.2$

$⟹0.5V_A+0.1V_B=0.2V_{A+B}....\left(1\right)$

$⟹V_A+V_B=V_{A+B}....\left(2\right)$

By solving equations (1) and (2), we get $\frac{V_A}{V_B}=\frac{1}{3}$

So, only option $A$ satisfies this condition.