Calculating EMPIRICAL Formulas & Mole-Gram conversions

What is the empirical formula if you have 36.84% nitrogen and 63.16% oxygen?

• NO
• N₂O₃
• N₂O₄
• N₂O₅

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements. (keep two decimal places throughout calculations)

• SO
• SO₂
• SO₃
• SO₄

A compound consists of 72.2% magnesium(Mg) and 27.8% nitrogen(N) by mass. What is the empirical formula?

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements.

• SO
• SO2
• SO3
• SO4

What is the empirical formula for a compound containing the following ratio:
3Na:1P:4O

• NaPO₄
• Na₃P₄O
• Na₃PO₄
• NaPO

What is the empirical formula for a compound containing: 92.30% carbon and 7.70% hydrogen

• CH
• CH₄
• C₂H₄
• C₂H₄

What is the empirical formula if you have 35.98% aluminum and 64.02% sulfur?

• AlS

• Al₂S

• AlS₂

• Al₂S₃

What is the mass of one mole of aluminum?

• 27.0 g/mol

• 54.0 g/mol

• 13.0 g/mol

• 14.0 g/mol

What is the mass of 4.5moles of CH₄? (Hint: converting moles to grams)

• 72.0 g

• 72.0 g/mol

• 72.0 mol

• 0.3 mol

What is the mass of 15 moles of water? (Hint: converting moles to grams)

• 0.8 g

• 270 g

• 0.8 mol

• 270 mol