Problema Solution
How much pure acid should be mixed with 5 gallons of a 40% acid solutionin order to get a 50% acid solution?
Answer provided by our tutors
let
x = gallons of pure acid that is 100% acid solution
100% of x gallons acid + 40% of 5 gallons acid = 50% of (x + 5) gallons acid
1*x + 0.4*5 = 0.5*(x+5)
x + 2 = 0.5x + 2.5
x - 0.5x = 2.5 - 2
0.5x = 0.5
x = 1 gallon
we need 1 gallon of pure acid.