In: Chemistry
A tablet of Benadryl (R), an antihistamine, has a mass of 0.49 g. It contains 25 mg of the active ingredient, diphenhydramine HCL. What percent of the tablet is active ingredient?
Mass of a tablet of Benadryl (R) = 0.49 g (given)
Mass of a tablet of Benadryl (R) in mg = 0.49 x 1000 = 490 mg.
Mass of the active ingredient, diphenhydramine HCL in a tablet of Benadryl (R) = 25 mg (given)
Percent of the active ingredient = (Mass of the active ingredient/ Mass of a tablet of Benadryl) x 100
= (25 mg/490mg) x 100 = 5.10 %
5.10 % of the tablet is active ingredient.