Answer:
- <u><em>He must use 50g of the 12% solution and 30 g of the 20% solution.</em></u>
<u><em></em></u>
Explanation:
Call x the amount of <em>12% boric acid </em>solution to be used.
- The content of acid of that is: 0.12x
Since he wants to make <em>80 grams</em> of solution, the amount of <em>20% boric acid</em> solution to be used is 80 - x.
- The content of acid of that is{ 0.20(80 - x).
The final solution is <em>15% </em>concentrated.
- The content of boric acid of that is 0.15 × 80 g.
Now you have can write your equation:
Solve:
That is 50 grams of the 12% solution of boric acid.
Calculate the amount of the 20% solution of boric acid:
That is 30 grams.
Then, he must use 50g of the 12% solution and 30 g of the 20% solution.