Percentage Composition of Compounds

Find the percent composition of Aspirin C9H8O4?

• 4.4%

• Molar Mass of Aspirin

• 108 g/mol

• Molar Mass of C9

• 35.6%

• H

• 60%

• C

• 180 g/mol

• O

Percent Composition is the ​ (a)   by ​ (b)   of each element in a compound.

• percentage

• mass

• compound

What is the percent by mass of fluorine in CaF₂ (gram-formula mass = 78 g/mol)?

• 24%

• 49%

• 49%

• 65%

What is the percent by mass of calcium in CaF₂ (gram-formula mass = 78 g/mol)?

• 24%

• 49%

• 51%

• 65%

Find the percent composition of Cu₂S?

• %Cu= 67.987 %S= 32.013

• %Cu= 79.854 %S= 20.145

• %Cu= 35.946 %S= 64.054

Which element in the compound potassium cyanide, KCN, has a percent composition of 60.97%?

• K

• C

• N

• None

Which of the following is NOT needed to calculate percent composition?

• Mass of specific element

• Molar Mass

• Avogadro's Number

• Division

Which of the following is a correct statement about composition of compound?

• Percentage composition of compound tells you how many elements are present.

• Percentage composition of compound tells you the name of an element.

• Percentage composition of compound tells you the percentage of the mass

• Percentage composition of compound tells you the percentage of the mass made up by each element in compound.

What is the percent composition of water (H2O)?

• 11.19% H, 88.81% O

• 33.33% H, 66.67% O

• 20% H, 80% O

• 10% H, 90% O

Tags

NGSS.HS-ESS2-5

Which element has the highest percent composition in glucose (C6H12O6)?

• Carbon

• Hydrogen

• Oxygen

• Nitrogen