What volumes of 10 M HCl and 3 M HCl should be mixed to get 1L of 6 M HCl solution?

Options

A. 200800
B. 700300
C. 250750
D. 400600

Answer

C

Explanation

Suppose x mL of 12 M HCl to be mixed with (1000-x) mL of 4 M HCl .
`M_(1)V_(1) + M_(2)V_(2) = M_(3)V_(3)`
` 12 xx x + 4 (1000-x) = 6 xx 1000`
`12 x + 4000 - 4x = 6000`
`8x = 2000`
`x = (2000)/(8) = 250 mL`
Volume of 12 M HCl required = 250 mL .
Volume of 4 HCl required `= 1000 - 250 = 750 mL`