Problema Solution
Heather wants to make a 36% acid solution. She has already poured 3 fluid ounces of a 72% acid solution into a beaker. How many fluid ounces of a 9% acid solution must she add to create the desired mixture?
Answer provided by our tutors
concentration = pure acid / total volume
amount of pure acid already poured:
3 * 0.72 = 2.16
desired concentration is 0.36, she needs to add 'v' ounces of 9% acid:
0.36 = (2.16 + 0.09v)/(3 + v)
solving for 'v' we have v=4
Heather needs to add 4 ounces of 9% acid solution to obtain a 36% acid solution