Calculating Percent Composition by Mass

This video tutorial explains how to calculate the percent composition of elements in compounds. It covers the formula for mass percent and demonstrates calculations using examples like sucrose and C5H9NO2. The tutorial also compares carbon content across different compounds and shows how to find the molar mass of a molecule using the mass percent of nitrogen.

What is the formula used to calculate the mass percent of an element in a compound?

• Mass of element * Total mass / 100

• Total mass / Mass of element * 100

• Mass of element / Total mass * 100

• Total mass * Mass of element / 100

How many carbon atoms are used in the calculation for sucrose?

• 22

• 5

• 11

• 12

What is the percent by mass of hydrogen in sucrose?

• 100%

• 51.4%

• 6.5%

• 42.1%

What is the percent by mass of oxygen in sucrose?

• 100%

• 42.1%

• 6.5%

• 51.4%

What is the total molar mass of C5H9NO2?

• 115.132 grams per mole

• 342.296 grams per mole

• 88.146 grams per mole

• 180.156 grams per mole

What is the mass percent of nitrogen in C5H9NO2?

• 52.16%

• 27%

• 12.1%

• 7.88%

What is the percent by mass of carbon in C5H9NO2?

• 52.16%

• 7.88%

• 12.1%

• 27%

What is the percent by mass of hydrogen in C5H9NO2?

• 52.16%

• 7.88%

• 12.1%

• 27%

Which compound has the highest percent of carbon by mass?

• C5H11OH

• CH4

• C6H12O6

• C2H7N

What is the molar mass of a molecule if the mass percent of nitrogen is 13.32%?

• 180.156 grams per mole

• 88.146 grams per mole

• 105.18 grams per mole

• 115.132 grams per mole