Calculating Percent Composition

Base your answer to the question on the information below.

Vitamin C, also known as ascorbic acid, is water soluble and cannot be produced by the human body. Each day, a person’s diet should include a source of vitamin C, such as orange juice. Ascorbic acid has a molecular formula of C₆H₈O₆ and a gram-formula mass of 176 grams per mole.

Which is a correct setup for calculating the percent composition by mass of oxygen in ascorbic acid?

Using the student’s data, what is the correct numerical setup for calculating the percent composition by mass of water in the hydrate?

• %H₂O = (2.13 g / 0.76 g) × 100

• %H₂O = (2.13 g / 21.37 g) × 100

• %H₂O = (0.76 g / 1.37 g) × 100

• %H₂O = (0.76 g / 2.13 g) × 100

Tags

NGSS.HS-PS1-7

What is the percent composition by mass of nitrogen in the compound N₂H₄ (gram-formula mass = 32 g/mol)?

• 13%

• 44%

• 88%

• 93%

Which compound has the greatest percent composition by mass of sulfur?

• BaS

• CaS

• MgS

• SrS

Complete the formula for % Composition.

a

b

c

100

total mass of compound

mass of element

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

• percentage

• mass

• compound

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

• 55%

• 72%

• 31%

• 46%

(Page 38-40) Complete the formula for % Composition.

a

b

c

mass of element

total mass of compound

100

Find the percent composition of Aspirin C9H8O4?

• 4.4%

• H

• 60%

• Molar Mass of C9

• 180 g/mol

• Molar Mass of Aspirin

• 35.6%

• C

• 108 g/mol

• O

Which compound has the highest percent composition by mass of strontium?

• SrCl₂

• SrI₂

• SrO

• SrS