I am lost on this homework at this time and my teacher is unavailble

Question

The human body can eliminate ethanol (through metabolism, evaporation, etc.) at an approximate rate of 15 g per hour. Given that one milliliter of ethanol has a mass of 0.789 g, how long will it take for the visitor’s body to rid itself of the ethanol?

Answer 1

Apparently you are studying dimensional analysis, so that is what we will use to solve this problem.

In all dimensional analysis, we want various units to cancel leaving us with the desired units that we want.

The problem does not state how much ethanol is to be eliminated, i.e. it doesn't state how much ethanol the person consumed. If we assume it is 178 ml (from your previous question), then we have the following:

178 ml x 0.789 g/ml x 1 hour/15 g = hours (note how ml cancel, and then how g cancel, leaving hours)

Answer = 9.4 hours

Answer 2

0.789g ethanol x 1 hour = 0.0526 hours or 3.16 minutes

15 g