Question

How much aspirin will remain after 12 hours if a person took a single dose of 300 mg? The t½ of aspirin is 3 hours.

a. 100 mg
b. 37.5 mg
c. 18.8 mg
d. No right choice.

Answer 1

Answer:

Correct answer is option c

Explanation:

Formula: Remaining quantity of compound$A=P(\frac{1}{2})^\frac{t}{T}$

Here,

P = Initial quantity of the compound = 300 mg

t = time that is elapsed = 12 hours

T = half life of the compound = 3 hours

$\therefore \,Remaining \,quantity \,of \,aspirin=300(\frac{1}{2})^\frac{12}{3} \\ =300\times\frac{1}{16} =18.75\approx18.8$

Hence, 18.8 g aspirin remain after 12 hours.