SOLUTION: How many ml of 30% acid should be added to pure acid to make 70 ml of 35% acid?

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: How many ml of 30% acid should be added to pure acid to make 70 ml of 35% acid?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 851007: How many ml of 30% acid should be added to pure acid to make 70 ml of 35% acid?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
If the percents are as volume per volume, then your solution(solving) is uncomplicated. If the percents are as weight per volume, then you must use, be given MORE information.

In case the concentrations given are percent weight per volume, you need to know the density of the 30% acid, call it d%5B1%5D; and the density of the pure 100% acid, call it d%5B2%5D.
-
Let u = the volume, mililiters, of 30% acid.
Let v = the volume of the pure acid.
The system of equations to arrange are these:
highlight_green%28%2830%2Au%2Ad%5B1%5D%2B100%2Av%2Ad%5B2%5D%29%2F70=35%29
-
highlight_green%28u%2Bv=70%29
-

Solve the simultaneous equations for u and v.


Similar requirements are important for your other percent acid mixture problem also.