Question 380613: How much pure acid should be mixed with 2 gallons of a 40% acid solution in order to get a 80% acid solution? Answer by ewatrrr(24785) (Show Source):
Hi,
Let x represent the amount of the 100% pure acid solution
1.00x + .40*2gal = .80*(x + 2gal)
solving for x
.20x = .40*2gal
x = 4 gal of pure acid needed.
CHECKING our Answer
4 + .8 = 4.8 = .8*6