Mole Toolkit Review Quiz

Which of the following is NOT needed to calculate percent mass composition?

• Molar Mass of each specific element

• Molar Mass of Compound

• Avogadro's Number
• Division

What is the percent by mass of sodium in NaCl?

• 39%
• 61%
• 35%
• 65%

The mass percent of hydrogen in methane (CH₄) is:

• 75%

• 92%

• 25%

• 4%

What is the mass percentage of carbon in carbon dioxide (CO₂)?

• 27.27%

• 42.86%

• 72.73%

• 72.72%

Find the percentage composition of Mg in Mg₃(PO₄)₂.

• 27.48% Mg

• 43.11% Mg

• 16.00% Mg

• 12.63% Mg

The mass % of aluminum in aluminum sulfate Al₂(SO₄)₃ is:

• 45.70%

• 7.89%

• 35.94%

• 15.77%

A formula with the lowest whole number ratio of elements in a compound is called

• Molecular Formula
• Chemical Formula
• Empirical Formula 
• Distance Formula

Which of the following is considered an empirical formula?

• CH₃COOH

• C₆H₁₂O₆
• H₂O

Which pair has the same empirical formula?

• NaCrO₄ and Na₂Cr₂O₇
• C₂H₄O₂ and C₆H₁₂O₆
• C₃H₆O₃ and C₂H₆O₂
• CH₄ and C₂H₆

A compound is made up of 40.05% S and 59.95% O by mass. Find the empirical formula for these elements.

• SO
• SO₂

• SO₃

• SO₄