7B.1

[Edmund Zhi 2B]

A certain beta blocker is eliminated in a first-order process with a rate constant of 7.6 * 10^-3 min^-1 at normal body temperature (37 C). A patient is given 20. mg of the drug. What mass of the drug remains in the body 5.0 h after administration?


How do we use the integrated rate law/rate low to figure this out if we are given only mass, not concentration?

[kristi le 2F]

Masses and concentrations are proportional. Through using the equation ln[A]t/[A]0, = -kt, we find that the proportion of [A]t to [A]0 is 1/10. So, 10% of the initial drug concentration remains in the body, which is (0.10)(20 mg) = 2.0 mg.

[Nico Medina]

I was wondering this too, thanks for the help!