2. Atoms & Elements

Why do chemists use the mole as a counting unit?

What is the mass of 6.02 × 10^{23} atoms of carbon-12?

How many molecules of H_2O are present in 2.7 moles of water?

How many hydrogen atoms are present in 1.00 mole of NH_3?

How many carbon atoms are present in 1.00 mol of C_2H_6?

Which of the following contains exactly Avogadro's number of atoms?

Which of the following numerical expressions gives the number of moles in a sample containing mass m (in grams) of a substance with molar mass M (in g/mol)?

How many silver atoms are present in 3.75 moles of silver (Ag)?

How many molecules are present in 0.500 moles of H_2?

How many moles of hydrogen atoms are present in 2.0 moles of ammonia (NH_3)?

How many atoms are present in one mole of carbon?

How many moles are present in 25.5 g of silver (Ag)? (Molar mass of Ag = 107.9 g/mol)

How many moles of silver atoms are present in 1.8 × 10^{20} atoms of silver (Ag)?

Which of the following best describes Avogadro's number?