Percent Composition & Empirical Formula

Find the percent composition of Copper (I) Sulfide?

• %Cu= 67.987 %S= 32.013

• %Cu= 79.854 %S= 20.145

• %Cu= 35.946 %S= 64.054

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

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

Which of the following is considered an empirical formula?

• CH₃COOH
• C₆H₁₂O₆
• H₂O

What is the percentage of oxygen in carbon dioxide?

• 27.3%

• 72.7%

• 30%

• 70%

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 if you have 81.82% carbon and 18.18% hydrogen?

• C3H8
• CH4
• C2H2
• C4H10

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

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

What is the percentage of chlorine in sodium chloride?

• 60.7%

• 39.3%

• 60%

• 40%

Given the following: 42.07% Na, 18.89% P, and 39.04% O, determine the empirical formula.

•  NaPO2
• Na2PO3
• Na3PO4
• NaPO4

What is the percentage of iron in iron (III) oxide?

• 30%

• 70%

• 40%

• 60%