A 5% alcohol solution is mixed with 15% alcohol solution to make a 25mlof a 9% solution. How much of each alcohol solution is used?

Answer 1

Let x be the number of ml of the 5% solution and y be the number of moles of the 9% solution.

0.09 * 25 = 0.05*x + 0.15y (alcohol content)

x + y = 25 (total volume)

Substitute 25-x for y in the first equation and solve for x.

2.25 = 0.05 x + 0.15(25-x) = 3.75 -0.10x
etc.