Two solutions of HCI, A and B, have concentrations of 0.5 N and 0.1 M respectively. The volume of solutions A and B required to make 2 litres of 0.2 N 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 + 1.25 L of B

Answer

A

Explanation

Let volume of solution A = xL
Volume of solution B = (2 - x)L
`M_1V_1 + M_2V_2 = M(V_1 + V_2)` ( for HCl = 0.1 M = 0.1 N)
`0.5 xx x + 0.1 (2-x) = 0.2 (2)`
`0.5 x + 0.2 - 0.1x = 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
= 1.5L