Solve the problem.
-How much pure acid should be mixed with 9 gallons of a 50% acid solution in order to get an 80% acid solution?
A)4.5 gal
B)22.5 gal
C)36 gal
D)13.5 gal

Question

Quizplus · Accepted Answer

To achieve an 80% acid solution, let x be the amount of pure acid (100%) to add. The initial solution has 9 gallons of 50% acid, which means it contains 4.5 gallons of pure acid. The total volume of the new solution will be (9 + x) gallons, and the amount of pure acid in it will be (4.5 + x) gallons. The equation for the concentration is: (4.5 + x) / (9 + x) = 0.8. Solving for x gives x = 13.5 gallons.

Solve the Problem. -How Much Pure Acid Should Be Mixed with 9 Gallons