Elemental Analysis of Hydrocarbons and Empirical Formulas

Professor Dave explains elemental analysis using hydrocarbons, focusing on determining empirical and molecular formulas. He describes a method involving combustion to analyze the carbon and hydrogen content in a sample, using benzene as an example. The video concludes with a call to subscribe for more tutorials.

What is a hydrocarbon composed of?

• Oxygen and nitrogen

• Carbon and hydrogen

• Hydrogen and nitrogen

• Carbon and oxygen

What are the products of hydrocarbon combustion?

• Carbon monoxide and water

• Carbon dioxide and water

• Oxygen and hydrogen

• Nitrogen and carbon dioxide

What is the purpose of the apparatus used in the experiment?

• To measure the temperature of the flame

• To absorb oxygen and nitrogen

• To weigh the hydrocarbon sample

• To absorb water and carbon dioxide

How much carbon is present in CO2 by mass?

• 44%

• 27.3%

• 12%

• 50%

What is the percent composition of carbon in benzene?

• 92.4%

• 7.6%

• 50%

• 27.3%

What is the empirical formula of benzene?

• C6H6

• CH

• C2H2

• C3H3

What is the ratio of carbon to hydrogen in the empirical formula of benzene?

• 1:1

• 1:2

• 2:1

• 3:5

What is the molecular mass of benzene?

• 92.4

• 78

• 13

• 44

How many units of the empirical formula are needed to form the molecular formula of benzene?

• 6

• 5

• 7

• 4

What is the molecular formula of benzene?

• C2H2

• C3H3

• C6H6

• CH