Percentage Composition of Compounds

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

• 55%

• 72%

• 31%

• 46%

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.

• 33.33%

• 66.67%

• 88.89%

• 11.11%

Tags

NGSS.HS-PS1-7

• 82.35%

• 17.65%

• 77.78%

• 22.22%

• Na

• Cl

• Both Na and Cl

• None