Module 5: Stoichiometry Review

One mole of silver has a mass of 107.9 grams. Approximately how many atoms of silver are present in one mole of silver? (5.01)

• 107 atoms

• 108 atoms

• 6 x 10²³ atoms

• 53 x 10²³ atoms

One mole of copper has a mass of 63.5 grams. Approximately how many atoms of copper are present in one mole of copper? (5.01)

• 63 atoms

• 64 atoms

• 32 x 10²³ atoms

• 6 x 10²³ atoms

One mole of zinc has a mass of 65.4 grams. Approximately how many atoms of zinc are present in one mole of zinc? (5.01)

• 32 x 10²³ atoms

• 6 x 10²³ atoms

• 66 atoms

• 65 atoms

Which of the following best defines the molar mass of a substance? (5.01)

• Mass, in grams, of each particle of the substance

• Total mass, in grams, of 100 particles of the substance

• Mass, in grams, of the nucleus of the substance's atoms

• Total mass, in grams, of all the particles in one mole of the substance

Which of the following best defines Avogadro's number? (5.01)

• Mass, in grams, of each particle of the substance

• Number of particles in one mole of a pure substance

• Mass, in grams, of the nucleus of the substance's atoms

• Total mass, in grams, of all the particles in one mole of the substance

Which of the following best defines one mole of a substance? (5.01)

• Mass, in grams, of each particle of the substance

• Mass, in grams, of the nucleus of the substance's atoms

• Amount of substance present in one atom of the substance

• Amount of substance present in Avogadro's number of particles of the substance

How many atoms of K are present in 195.49 grams of K? (5.01)

• 3.0110 x 10²⁴

• 6.0220 x 10²⁴

• 1.1772 x 10²⁶

• 4.5797 x 10²⁷

How many atoms of Mg are present in 97.22 grams of Mg?(5.01)

• 6.022 x 10²³

• 2.408 x 10²⁴

• 4.818 x 10²⁴

• 5.855 x 10²⁵

How many atoms of Ca are present in 80.156 grams of Ca? (5.01)

• 1.2044 x 10²⁴

• 2.4088 x 10²⁴

• 4.8270 x 10²⁵

• 1.9346 x 10²⁷

Which formula can be used to calculate the molar mass of water (H₂O)? (5.02)

• 2 x molar mass of H + 2 x molar mass of O

• molar mass of H + 2 x molar mass of O

• 2 x molar mass of H + molar mass of O

• molar mass of H + molar mass of O