Chemistry

Chemistry

Problem

A patient receives a 250 mg dose of a drug whose concentration in the bloodstream decays exponentially with a half-life of 6 hours. When the concentration falls to 100 mg, what are the elapsed time tt and the instantaneous rate of change dCdt\dfrac{dC}{dt} at that moment? a) t≈5.5 hr; dCdt≈−16.7 mg/hrt \approx 5.5\ \text{hr};\ \dfrac{dC}{dt} \approx -16.7\ \text{mg/hr} b) t≈7.9 hr; dCdt≈−11.6 mg/hrt \approx 7.9\ \text{hr};\ \dfrac{dC}{dt} \approx -11.6\ \text{mg/hr} c) t≈7.9 hr; dCdt≈−18.9 mg/hrt \approx 7.9\ \text{hr};\ \dfrac{dC}{dt} \approx -18.9\ \text{mg/hr} d) t≈7.9 hr; dCdt≈−28.9 mg/hrt \approx 7.9\ \text{hr};\ \dfrac{dC}{dt} \approx -28.9\ \text{mg/hr}

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