Percent Composition

What percentage of the total atomic mass of carbon monoxide (CO) is composed of carbon?

• 29%

• 43%

• 57%

• 73%

What percentage of the total atomic mass of carbon monoxide (CO) is composed of oxygen?

• 29%

• 43%

• 57%

• 73%

What percentage of the total atomic mass of magnesium bromide (MgBr₂) is composed of bromine? Hint - consider the mass of both atoms of bromine in your calculation.

• 13%

• 43%

• 63%

• 87%

What percentage of the total atomic mass of lithium phosphide (Li₃P) is composed of phosphorus?

• 13%

• 29%

• 40%

• 60%

Find the percent composition of Aspirin C9H8O4?

• 180 g/mol

• Molar Mass of Aspirin

• 108 g/mol

• H

• 4.4%

• O

• 35.6%

• Molar Mass of C9

• 60%

• C

(Page 38-40) Percent Composition is the ​ (a)   by ​ (b)   of each element in a compound.

• percentage

• mass

• compound

Complete the formula for % Composition.

a

b

c

mass of element

100

total mass of compound

Tags

NGSS.HS-PS1-7

Complete the formula for % Composition.

a

b

c

total mass of compound

mass of element

100

The percent, by weight, of carbon in C₄H₈O₃ is (a)   .

• 55%

• 72%

• 31%

• 46%

What percentage of the total atomic mass of calcium nitrate (Ca(NO₃)₂) is composed of nitrogen? Hint - another way to think of calcium nitrate is Ca(NO₃)(NO₃).

• 17%

• 24%

• 29%

• 59%