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. 1.0 L of A + 1.0 L of B
D. 0.75 L of A + 125 L of B

Answer

A

Explanation

Let volume of solution A=xL
Volume of solution B = (2-x) L
`M_(1)V_(1) + M_(2)V_(2) = M(V_(1)+V_(2))`
`0.5 xx x + 0.1(2-x) = 0.2(2)`
`0.5 x + 0.2 - 0.1 x = 0.4`
`0.4 x = 0.2`
`x=0.2/0.4 = 0.5 L`
Vol. of A = 0.5 L, Vol. of B = 2.0 - 0.5 = 1.5 L