The volumes of two HCl solution A `(0.5 M)` and `B (0.1M)` to be mixed for preparing 2 L of 0.2 M HCl are

Options

A. 0.5 L of A + 1.5 L of B
B. 1.5 L of A + 0.5 L of B
C. 1 L of A + 1 L of B
D. 0.75 L of A + 1.25 L of B

Answer

A

Explanation

. Let x L of A and (2 – x) L of B are mixed.
`M_1V_1+M_2V_2=M_R(V_1+V_2)`
`0.5xxx+0.1(2-x)=0.2xx2`
`(0.5-0.1)x=0.4-0.2`
`0.4x=0.2rArrx-0.5L`
`:.` 0.5 L of A and 1.5 L of B should be mixed.