Question 29805
look at my Lesson on "Mixture" questions.


BEFORE: 5 gallons 90% acid and x gallons of 0% acid
AFTER: (5+x) gallons 70% acid


5*0.90 + x*0.00 = (5+x)*0.70
4.5 + 0 = 3.5 + 0.7x
1 = 0.7x
x = 1/0.7
x = 1.43 gallons of distilled water (to 2dp)


jon.