Mole Practice Quiz

Calculate the molar mass of Ba(C₂H₃O₂)₂

• 255.3 g/mol

• 237.3 g/mol

• 228.3 g/mol

• 196.3 g/mol

Calculate the molar mass of Cu₂O.

• 37 g/mol

• 45 g/mol

• 79.5 g/mol

• 143 g/mol

What is the percent by mass of oxygen in MgO?

• 20%
• 40%
• 50%
• 60%

What is the percent by mass of magnesium in MgO?

• 20%
• 40%
• 50%
• 60%

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

• 20%
• 27%
• 46%
• 53%

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 definition for Avogadro's number?

• number of grams per one mole of a substance

• whole number ratio that is a multiple of a chemical formula

• simplest, whole number ratio of a chemical formula

• 6.02 x 10²³ particles per one mole of a substance

How many moles are present in 32.3 grams of carbon dioxide (CO₂)?

• 44.01 moles
• 1421.52 moles
• 32.3 moles
• 0.73 moles

What is Avogadro's Number? 

• 6.02 x 10²³
• - 6.02 10²³
• 6.02 x 10²²
• 6,020,000,000,000

How many moles are in 20 grams of Ca (Calcium)?

• 0.5 
• 1
• 3
• 20