Empirical Formulas Review

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

• SO

• SO₂

• SO₃

• SO₄

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

• NaPO₂

• Na₂PO₃

• Na₃PO₄

• NaPO₄

What is the empirical formula if you have 81.82% carbon and 18.18% hydrogen?

• C3H8

• CH4

• C2H2

• C4H10

What is the percent by mass of sodium in NaCl?

• 39%

• 61%

• 35%

• 65%

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

• 20%

• 27%

• 46%

• 53%

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

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

• SO

• SO2

• SO3

• SO4

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? (NaCl)

• 60.7%

• 39.3%

• 60%

• 40%