Unit 9 Review: The mole concept

What is the percent composition by mass of sulfur in the compound MgSO₄ (gram formula mass = 120 g/mol)?

• 20%
• 27%
• 46%
• 53%

What is the percent by mass of calcium in CaF₂ (gram-formula mass = 78 g/mol)?

• 24%
• 49%
• 51%
• 65%

In which compound is the percent composition by mass of Cl equal to 42%?

• HClO (gram formula mass = 52 g/mol)
• HClO₂ (gram formula mass = 68 g/mol)
• HClO₃ (gram formula mass = 84 g/mol)
• HClO₄ (gram formula mass = 100 g/mol)

What is the percent by mass of fluorine in CaF₂ (gram-formula mass = 78 g/mol)?

• 24%
• 49%
• 51%
• 65%

What is the molar mass of B₂(CO₃)₃?

• 81.632 g/mol
• 94.842 g/mol
• 38.822 g/mol
• 201.648 g/mol

What is the molar mass of dihydrogen dioxide (H₂O₂)?

• 48 g/mole
• 34.02 g/mole
• 36.5 g/mole
• 35.5 g/mole

What are the units for molar mass?

• grams
• amu
• grams/mole
• liters

The best definition for a mole provided below is

• The SI unit for the mass of something
• The SI unit for the amount of a substance
• The SI unit for the volume of something
• The SI unit for the area of a substance

The number 6.02 x 10²³, which is the number of particles found in a mole. 

• molar mass
• mole
• Avogadro's number
• hydrate

How many moles are in 3.01 x 10²² atoms of magnesium?

• 0.0500 moles
• 1.81 x 10⁴⁶ moles
• 5.00 x 10²¹ moles
• 5.00 moles