Question

What volume of 6M HCl and 2M HCl should be mixed to get one litre of 3M HCl?

Answer 1

Suppose the volume of 6M HCl required to obtain 1L of 3M HCl = XL

Volume of 2M HCl required = (1-x)L

Applying the molarity equation

M1V1 + M2V2 = M3V3

6MHCl + 2MHCl = 3MHCl

6x+2(1-x) = 3x1

6x+2-2x = 3

4x = 1

x = 0.25L

hence, volume of 6M HCl required = 0.25L

Volume of 2M HCl required = 0.75L