## General Chemistry: Principles and Modern Applications (10th Edition)

a) Two tablets contain 67 mg of aspirin. b) The dosage rate is 0.94 mg of aspirin per kg body mass. c) It takes $1.5 * 10^{4}$ days to consume 1 kg of aspirin.
a) 2 aspirin tablets contain 2 * 5.0 = 10.0 gr of aspirin. 15 gr = 1.0 g 1 gr = 1.0 / 15 g = 0.06666666667 g 10.0 gr = 0.6666666667 g 0.6666666667 g = 66.66666667 mg Rounding to 2 significant figures gives 67 mg. So two tablets contain 67 mg of aspirin. b) Body mass = 155 lb 2.205 lb = 1 kg 1 lb = 1/2.205 kg = 0.4535147392 kg 155 lb = 155 * 0.4535147392 kg = 70.29478458 kg. Dosage rate = 66.66666667 mg of aspirin per 70.29478458 kg body mass. This is 66.66666667 / 70.29478458 mg of aspirin per kg body mass. This is 0.943870968 mg of aspirin per kg body mass. Rounding to 2 significant figures gives 0.94 mg of aspirin per kg body mass. c) Rate of consumption = 2 tablets per day. 2 tablets contain 66.66666667 mg of aspirin (see a). 1 kg = $10^{6}$ mg $10^{6}$ / 66.66666667 = 15000 days. So at the given rate of consumption it takes 15000 days to consume 1 kg of aspirin. Rounding to 2 significant figures gives 1.5 * $10^{4}$ days.