Question

In chemistry class 12 L of 11% alcohol solution must be mix with a 20% solution to get a 14% solution how many liters of the 20% solution are needed

Answer 1

6 L

Explanation:

You want to know the number of liters of 20% solution to mix with 12 liters of 11% solution to make a 14% solution.

Setup

Let x represent the quantity of 20% solution. Then the amount of alcohol in the final solution is ...

0.11(12) +0.20x = 0.14(12+x)

Working

Simplifying the equation, we have ...

1.32 +0.20x = 1.68 +0.14x

0.06x = 0.36 . . . . . . . . . . . . . subtract 0.14x+1.32

x = 6 . . . . . . . . . . . . . . . . . divide by 0.06

6 liters of 20% solution are needed.