Empirical Formula and Percentage Composition

Find the percent compositions of all of the elements in the compound (NH₄)₃PO₄.

A compound contains 75.46% carbon, 4.43% hydrogen, and 20.11% oxygen by mass. It has a molar weight of 318.31 g/mol. What is the empirical formula and molecular formula?

2.40 g of an explosive, J, contains 0.473 g of nitrogen. J also contains 33.8% carbon and 1.41% hydrogen by mass. The remainder of J is oxygen. What is the empirical formula of J?

• C₄HNO₂

• CH₂N₂O

• C₂HNO₂

• CHNO

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

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

•  NaPO2

• Na2PO3

• Na3PO4

• NaPO4

Tags

NGSS.HS-PS1-7

Glycerol has a molar mass of 92.09g/mol. Its percent composition is: 39.12% C, 8.75% H, and 51.12% O. What is the molecular formula for glycerol?

• C₂H₃O₂

• CH₂O

• C₂H₄O₂

• C₃H₈O₃

Which one is the empirical formula?

• CH

• CH₃

• C₂H₃

• C₄H₆

Tags

NGSS.MS-PS1-1

What percentage of the total atomic mass of magnesium bromide (MgBr₂) is composed of bromine? Hint - consider the mass of both atoms of bromine in your calculation.

• 13%

• 43%

• 63%

• 87%

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

• 27.48% Mg

• 43.11% Mg

• 16.00% Mg

• 12.63% Mg

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

• Molecular Formula

• Chemical Formula

• Empirical Formula 

• Distance Formula

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