If a solution of iodine and alcohol contains 4 ounces of iodine and 16 ounces of alcohol, how many ounces of alcohol need to evaporate so that the ratio of iodine to the solution is 2 to 3?

14 ounces

Step-by-step explanation:

Iodine quantity + alcohol quantity = solution quantity

4 + 16 = 20

Initial ratio of the iodine: alcohol : solution = 4:16:20

Therefore to get the solution to be in ratio (2:Unknown:3)

then the Alcohol must evaporate to

Solution quantity - iodine quantity

3 - 2 = 1

This implies that new ratio of the iodine: alcohol : solution = 2:1:3

However since iodine does not evaporate the ratio will be (multiply all by 2)

4:2:6

Initial quantity of alcohol - new quantity of alcohol = evaporated quantity

16ounces - 2 ounces = 14 ounces