Answer:
The researcher needs 20 milliliters of 11 percent concentrated acid and 10 milliliters of 2 percent concentrated acid.
Step-by-step explanation:
Given that a researcher wants a 30 milliliter acid solution with a concentration of 8%, and she has concentrations of 2% and 11%, to determine how much of each solution must she use to get the desired concentration, the following calculation must be performed:
100 x 0.11 + 0 x 0.02 = 11
90 x 0.11 + 10 x 0.02 = 10.1
80 x 0.11 + 20 x 0.02 = 9.2
70 x 0.11 + 30 x 0.02 = 8.3
66.666 x 0.11 + 33.333 x 0.02 = 8
30 x 0.6666 = 20
Therefore, the researcher needs 20 milliliters of 11 percent concentrated acid and 10 milliliters of 2 percent concentrated acid.
