Question

Shelby and calvin are doing a chemistry experiment. they need 5 ounces of a solution that is 65% acid and 35% distilled water. there is no pure acid in the lab, but they have two flasks of other dilute acid mixtures. flask a contains 70% acid and 30% distilled water. flask b contains 20% acid and 80% distilled water. how many ounces do they need from each flask to make their mixture

Answer 1

Let A denote the ounces of solution cast-off from Flask A whereas     B is the amount of ounces of solution used from flask B     Then     0.7 * A is the number of ounces of acid in solution from Flask A     0.2 * B is the number of ounces of acid in solution from Flask B     0.65(5) is the total number of ounces of acid in the final solution Now write equations for total ounces of solution and total ounces of acid A + B = 5                0.7A + 0.2B = 0.65 * 50.7(4.5) + (0.2)(0.5) = 3.253.15 + .1 = 3.25The answer is A =4.5, b = 0.5