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 + 1.5L` 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_(1)V_(1)+M_(2)V_(2)=M_(R)(V_(1)+V_(2))`
`0.5xxx+0.1(2-x)=0.2xx2`
`(0.5-0.1)x=0.4xx-0.2`
`0.4x=0.2`
`x=0.5L`
`:.` 0.5 L of A and 1.5 L of B should be mixed/