The volume of 10 N and 4 N HCl required to make 1 L of 7 N HCl are

Options

A. 0.50 L of 10 N HCl and 0.50 L of 4 N HCI
B. 0.60 L of 10 N HCl and 0.40 L of 4 N HCI
C. 0.80 L of 10 N HCl and 0.20 L of 4 N HCI
D. 0.75 L of 10 N HCl and 0.25 L of 4 N HCI.

Answer

A

Explanation

Let volume of 10N HCl to be mixed with 4N = HCl = x
volume of 4N required = 1 - x
`N_1V_1 + N_2V_2 = N_3V_3`
`10 xx x + 4 xx (1 - x) = 7 xx 1`
` 10 x + 4 - 4x = 7`
`6x = 3`
` x = 3//6 = 0.5 L`
volume of 10N HCl required = 0.5 L
volume of 4N HCl required = 1 - 0.5 = 0.5L