SOLUTION: how many gallons of hydrochloric acid must be added to 12 gallons of a 30% solution to obtain a 40% solution?

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: how many gallons of hydrochloric acid must be added to 12 gallons of a 30% solution to obtain a 40% solution?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 564714: how many gallons of hydrochloric acid must be added to 12 gallons of a 30% solution to obtain a 40% solution?
Answer by Maths68(1474) About Me  (Show Source):
You can put this solution on YOUR website!
Solution A
Amount = 12 gallons
Concentration =30% =0.3
Solution B
Amount = x
Concentration =100% = 1 (Pure Hydrochloric acid)
Resultant Solution
Amount =12+x
Concentration =40%=0.4
[Amount Solution A * Concentration A] + [Amount Solution B * Concentration of B] = Amount of Resultant * Concentration of resultant
12*0.3 + x*1 = (12+x)*0.4
3.6+x=4.8+0.4x
x-0.4x=4.8-3.6
0.6x=1.2
0.6x/0.6=1.2/0.6
x=2

2 gallons of hydrochloric acid (pure) must be added to 12 gallons of a 30% solution to obtain a 40% solution.