The Formula Feud

Percent Composition

100

What is the percent composition of lithium in lithium oxide (Li₂O)?

Molar Mass of Li₂O= 29.8g/mol

Percent Composition:46.3%

200

Calculate the percent composition of carbon in carbon dioxide (CO₂). 

Percent Composition: 27.27%

300

Calculate the percent composition of phosphorus in magnesium phosphate Mg₃(PO₄)_2. 

Percent composition: 23.58%

400

Calculate the percent composition of oxygen in magnesium hydroxide.

Percent Composition: 54.89%

500

Calculate the percent composition of both carbon and hydrogen in acetamide (C₂H₅NO).

Percent composition for C: 40.668%

Percent composition for H: 8.533%

Empirical Formula

100

A compound has 40.68% carbon, 5.12% hydrogen, and 54.20% oxygen. Calculate the empirical formula 

Empirical Formula:

C₂H₃O₂

200

Calculate the empirical formula of a compound that is 85.6% Carbon, and 14.4% Hydrogen. 

a)CH₂

b)CH

c)C₂H₄

d)C₂H

Correct Answer:

a) CH₂

300

Determine the Empirical Formula for a lactic acid that is 40.0% Carbon, 6.71% hydrogen, and 53.3% Oxygen. 

Empirical Formula

CH₂O

400

Write the empirical for a compound that is 21.20% Nitrogen, 6.06% Hydrogen, 24.30% Sulfur, and 48.45% Oxygen.

Empirical Formula: 

N₂H₈SO₄

500

Given that a 95.2g sample contains 40.8g of carbon and 54.4g of Oxygen, determine the empirical formula

a)C₂O₂

b)CO₃

c)CO 

d)C₂O

Empirical Formula:

c)CO

Molecular Formula

100

What is the molecular formula for a compound with an empirical formula of C₂OH₄ and a molar mass of 44 g/mol. 

Molecular Formula:

C₂OH₄

200

What is the molecular formula for a compound with an empirical formula of C₄H₄O and molar mass of 136 g/mol. 

Molecular Formula:

C₈H₈O₂

300

The empirical formula of a compound is CH₂, its molar mass is 56 g/mol. Given this, find the molecular formula for this compound. 

Molecular Formula:

C₄H₈

400

Find the molecular formula for a compound with an empirical formula of CFBrO and a molar mass of 254.7 g/mol.

Molecular Formula:

C₂F₂Br₂O₂

500

What is the molecular formula of a compound containing 65.5% carbon, 5.5% hydrogen, and 29.0% oxygen, and a molar mass of 110 grams/mole?

BONUS for 100 pts* Determine the empirical formula and it's molar mass as well

Molecular Formula: C₆H₆O₂

Bonus* Empirical Formula: C₃H₃O with a mass of: 55 g/mol

Emprical/Molecular

100

True or False

The molecular formula for a compound is a multiple of the compound's empirical formula.

True!

200

Empirical or Molecular?

C₂H₄O₂N₃

Empirical

300

Empirical or Molecular?  

CaC₂H₂0₆

Empirical

400

Empirical or Molecular

C₁₆H₂₄O₁₆N₄

Molecular

500

True or False

The empirical formula will always be greater than the molecular formula. 

False