Multiple ChoiceHow many moles are present in 22 grams of argon (Ar)? (Atomic mass of Ar = 39.95 g/mol)
Multiple ChoiceA sample contains 18.0 g of water (H_2O). What is the number of moles present in the sample?
Open QuestionHow many sodium ions are contained in 99.6 mg of Na2SO3? The molar mass of Na2SO3 is 126.05 g/mol.
Multiple ChoiceHow many grams are present in a sample of calcium (Ca) that contains 2.71 × 10^{20} atoms?