Molar Mass and Percent Composition

In which compound is the percent composition by mass of Cl equal to 42%?

• HClO (gram formula mass = 52 g/mol)

• HClO₂ (gram formula mass = 68 g/mol)

• HClO₃ (gram formula mass = 84 g/mol)

• HClO₄ (gram formula mass = 100 g/mol)

What is the percent by mass of N in (NH₄)₂S?

• 47.1%

• 68.1%

• 44.1%

• 41.1%

Which conversion factor should be used to solve the following, "How many moles in 28 grams of CO₂?"

• mol = 22.4 L 

• mol = 44.01 g

• mol = 6.02x10²³ atoms

• more than one

What is the molar mass of Hydrogen Peroxide (H₂O₂)?

• 48 g/mole

• 34.02 g/mole

• 36.5 g/mole

• 35.5 g/mole

Which element has an abundance of 39.03% in the compound sodium phosphate, Na₃PO₄

• Na

• P

• O

• None of the above

Tags

NGSS.MS-PS1-1

What is the molar mass of CO₂?

• 12 g/mol

• 16 g/mol

• 32 g/mol

• 44 g/mol

What are the units in molar mass?

• grams

• moles

• moles/gram

• grams/mole

Gallium nitride (GaN) is an important material in computer chips. What is the percent composition of gallium in gallium nitride?

• 83%

• 17%

• 100%

• 0.8327

Calculate the molar mass of Cu₂O.

• 37 g/mol

• 45 g/mol

• 79.5 g/mol

• 143 g/mol

Calculate the molar mass of NH₄NO₂

• 50 g/mol

• 60 g/mol

• 64 g/mol

• 78 g/mol