Final answer:
The decrease factor of the medicine over 1.5 hours depends on the drug's pharmacokinetics and cannot be precisely determined without specific data on concentrations.
Step-by-step explanation:
The question relates to the decrease in medicine concentration over a period, which is typically described via pharmacokinetics, a topic within Chemistry. To understand by what factor the medicine decreased in the first hour and a half, we would need specific data on the concentration of the medicine at the start and at the 1.5-hour mark. Assuming this is a first-order reaction, which is common for medications, the concentration would decrease by a factor relating to its half-life. If a medication has a half-life of 1 hour, for instance, then after 1.5 hours, a bit more than half of the medication would remain.
Without the exact figures, we cannot provide a precise factor; nonetheless, if the question provided a starting concentration and a concentration after 1.5 hours, you could calculate the factor by dividing the latter by the former. One must also consider if the drug follows linear pharmacokinetics, as this will dictate if a consistent proportion of the drug is eliminated over equal time intervals.