Answer:
The proportion of acid at 70% that the chemist must use will be 77.8%, while the remaining 22.2% will be acid at 25%.
Step-by-step explanation:
Since the chemist has 100 ml of solution with 25% acid, and wants to obtain a solution of 60% acid by mixing the first with another 70% acid solution, to determine how much of each solution the chemical should use necessary to perform the following calculation:
70 x 1 + 25 x 0 = 70
70 x 0.9 + 25 x 0.1 = 65.5
70 x 0.8 + 25 x 0.2 = 61
70 x 0.7 + 25 x 0.3 = 56.5
Therefore, the proportion to be used is between 70% and 80% of acid at 70%, and 20% to 30% of acid at 25%.
70 x 0.75 + 25 x 0.25 = 58.75
70 x 0.76 + 25 x 0.24 = 59.2
70 x 0.77 + 25 x 0.23 = 59.65
70 x 0.78 + 25 x 0.22 = 60.1
Thus, the proportion should be between 77 and 78% of acid at 70% and 22 and 23% of acid at 25%.
70 x 0.778 + 25 x 0.222 = 60.01
Thus, finally, the proportion of acid at 70% that the chemist must use will be 77.8%, while the remaining 22.2% will be acid at 25%.
