Empirical and molecular Formula

Find the percent composition of Cu₂S?

• %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

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

• 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 molecular formula for a compound with the empirical formula: K₂SO₄ and a molecular mass of 696g.

• K₂SO₄ 
• K₈SO₁₆
• K₈S₄O₈ 
• K₈S₄O₁₆ 

What is the molecular formula of a compound with an empirical formula of C₂OH₄ and a molecular mass of 88 grams per mole?

• C₂O₄H₈

• C₈O₂H₄

• C₄O₂H₈

• C₄O₈H₂

What is the definition of empirical formula

• A chemical formula that shows all elements in a molecule

• A chemical formula that shows number of moles all elements in a molecule

• A chemical formula that shows simplest ratio of all elements in a molecule

• A chemical formula that shows mass of all elements in a molecule

What is the meaning of molecular formula?

• A chemical formula that show actual number of moles of each element in a molecule

• A chemical formula that shows actual number of charge of each element in a molecule

• A chemical formula that shows actual number of electrons of each element in a molecule

• A chemical formula that shows actual number of atoms of each element in a molecule