How much of 30% hcl and 45% hcl would be needed to mix and produce 50 liters of 35% hcl?

42.8572 L of 30% HCl and 7.1428 L of 45% HCl would be needed to mix and produce 50 liters of 35% HCl.

Explanation:

Let volume of  30% HCl solution required to make 35% of HCl solution be x

Volume of 45% of HCl required to make 35% of HCl solution be y

Volume of solution required = 50 L

x + y = 50 ..(1)

30% of x +45 % of y = 35% of 50

3x + 45y = 1750 ..(2)

Solving equation (1) and (2):

x = 42.8572 L

y =7.1428 L

42.8572 L of 30% HCl and 7.1428 L of 45% HCl would be needed to mix and produce 50 liters of 35% HCl.