Exploring Percent Composition Concepts

What is the purpose of calculating molar mass in chemistry?

• To find the boiling point of a compound

• To weigh specific numbers of atoms or molecules

• To calculate the number of molecules in a sample

• To determine the color of a compound

What percentage of water's mass is made up by hydrogen?

• 11%

• 89%

• 23%

• 35.5%

How is the percent composition of an element in a compound calculated?

• Total volume of the compound / Mass of the element * 100

• Mass of the element / Total volume of the compound * 100

• Total mass of the compound / Mass of the element * 100

• Mass of the element / Total mass of the compound * 100

What is the molar mass of sodium chloride?

• 58.5 g/mol

• 107 g/mol

• 112 g/mol

• 18 g/mol

What is the percent composition of chlorine in sodium chloride?

• 52%

• 61%

• 57%

• 39%

What does the subscript '3' in Fe(OH)3 indicate?

• There is 1 iron and 3 oxygen atoms

• There are 3 hydroxide groups

• There are 3 iron atoms

• There is 1 iron and 3 hydrogen atoms

What is the percent composition of iron in iron hydroxide?

• 61%

• 3%

• 45%

• 52%

How many oxygen atoms are there in titanium oxide Ti4O4?

• One

• Four

• Two

• Eight

What is the percent composition of oxygen in titanium oxide?

• 43%

• 57%

• 45%

• 52%

Why does oxygen have a higher percent composition in titanium oxide despite its lower molar mass compared to titanium?

• Because oxygen has a higher atomic number

• Because oxygen is more reactive

• Because oxygen atoms are larger

• Because there are more oxygen atoms