Question

The rate at which a certain drug is eliminated by the body follows first-order kinetics, with a half life of 68 minutes. Suppose in a particular patient the concentration of this drug in the bloodstream immediately after injection is 0.12/μgmL. What will the concentration be 340 minutes later? Round your answer to 2 significant digits.

Answer 1

Answer:

The concentration would be; 0.0038 μgmL

Explanation:

Half life, t1/2 = 68 minutes

Initial Conc. [A]o = 0.12/μgmL

Final Conc [A] = ?

Time. k = 340 minutes

ln[A] = ln[A]o - kt

t1/2 = ln2 / k

k = 0.693 / t1/2  = 0.693 / 68 = 0.01019

ln[A] = ln (0.12) - 0.01019 (340)

ln[A] = -2.1203 -3.4646

ln[A] = -5.5849

[A] = 0.00375 ≈ 0.0038 μgmL