Answer:
- 750 mL of 0.23% solution
- 250 mL of 0.03% solution
Explanation:
Let x represent the quantity (in liters) of the higher percentage solution, the 0.23% solution. Then 1-x will be the quantity of 0.03% solution. The amount of salt in the mix is ...
0.23%·x +0.03%·(1 -x) = 0.18%·1
Multiply by 100% and subtract 3:
20x = 15
x = 15/20 = 0.75 . . . . liters of 0.23% solution
1-x = 1-0.75 = 0.25 . . liters of 0.03% solution
The lab tech needs 750 mL of 0.23% solution and 250 mL of 0.03% solution.