Question

Doreen Schmidt is a chemist. She needs to prepare 36 ounces of a 15% hydrochloric acid solution. Find the amount of 18% solution and the amount of 9% solutionshe should mix to get this solution.How many ounces of 18% axis solution should be in the mixture?How many ounces is the 9% axis solution should be in the mixture?

Answer 1

SOLUTION

Let the ounces for the 18% mixture be x.

So, the ounces for the 9% mixture will be

$36-x$

So, this means that

$x(\frac{18}{100})+(36-x)(\frac{9}{100})=36(\frac{15}{100})$

Solving this, we have

$\begin{gathered} x(\frac{18}{100})+(36-x)(\frac{9}{100})=36(\frac{15}{100}) \\ 0.18x+(36-x)0.09=36(0.15) \\ 0.18x+3.24-0.09x=5.4 \\ 0.18x-0.09x=5.4-3.24 \\ 0.09x=2.16 \\ x=\frac{2.16}{0.09} \\ x=24 \end{gathered}$

So, the for 18%, we have 24 ounces.

For 9%, we have

$\begin{gathered} 36-24= \\ =12 \end{gathered}$

Hence for 9%, we have 12 ounces