SOLUTION: I want to find out how much water needs to be added to one gallon of a 75% phosphoric acid solution to create a 6% acid solution.

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: I want to find out how much water needs to be added to one gallon of a 75% phosphoric acid solution to create a 6% acid solution.      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 782912: I want to find out how much water needs to be added to one gallon of a 75% phosphoric acid solution to create a 6% acid solution.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
75% phosphoric acid is about 11.67 pounds per gallon. The percentage is expected weight per weight.
Water is 8.345 pounds per gallon.

Let w = how many pounds of water to add.

11.67%2A0.75%2F%28w%2B11.67%29=0.06, as decimal fractions instead of as percents.
6%28w%2B11.67%29=11.67%2875%29
6w=%2811.67%29%2875%29-6%2811.67%29
6w=11.67%2875-6%29
6w=11.67%2869%29
w=%2811.67%29%2869%29%2F6
highlight%28w=134%29 pounds of water.
As volume, 134%2F8.345=highlight%2816.1%29 gallons of water.