Question

Doreen Schmidt is a chemist. She needs to prepare 24 ounces of a 9% hydrochloric acid solution. Find the amount of 12% solution and the amount of 6% solution she should mix to get this solution.
PLEASE HELP ME
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Answer 1

Answer:

Step-by-step explanation:

So we need to balance two things here.  The overall volume, and the amount of hydrochloric acid.

Let's say x is the volume of the 12% solution and y is the volume of the 6% solution.

The sum of the volumes equals the total volume:

x + y = 24

And the sum of the amounts is the total amount:

0.12 x + 0.06 y = 0.09 (24)

We now have two equations and two variables.  We can solve this system of equations with either substitution or elimination.  Using substitution:

x = 24 - y

0.12 (24 - y) + 0.06 y = 0.09 (24)

2.88 - 0.12 y + 0.06 y = 2.16

0.72 = 0.06 y

y = 12

x = 24 - 12 = 12

So she needs to mix 12 ounces of 12% solution with 12 ounces of 6% solution to get 24 ounces of 9% solution.