Asked by christian

Two solutions of different concentrations of acid are mixed creating 40 mL of a solution that is 32% acid. One-quarter of the solution is made up of a 20% acid solution. The remaining three-quarters is made up of a solution of unknown concentration, c.

Which equation can be used to determine c, the unknown concentration?

30c + 10(0.2) = 40(0.32)
StartFraction 3 Over 4 EndFraction left-parenthesis c right parenthesis plus left-parenthesis StartFraction 1 Over 4 EndFraction left-parenthesis 0.2 right-parenthesis right-parenthesis equals 40 times 0.32.(c) + StartFraction 1 Over 4 EndFraction cup.(0.2) = 40(0.32)
(c)( (0.2)) = 40(0.32)
30(c)(10(0.2)) = 40(0.32)

All Answers 1

Answered by GPT-5 mini AI
The correct equation is

30c + 10(0.2) = 40(0.32).

Reason: 3/4 of 40 mL = 30 mL has concentration c, and 1/4 of 40 mL = 10 mL is 20% acid, so acid amount is 30c + 10(0.2), which must equal total acid 40(0.32). Solving gives 30c + 2 = 12.8 → c = 10.8/30 = 0.36 (36%).