Chemistry NCFE Review Pt 3

What is the molar mass of CO₂?

• 12.40 g/mol

• 16.55 g/mol

• 32.21 g/mol

• 44.00 g/mol

What are the units for molar mass?

• grams

• AMU

• g/mol

• mole

What is the molar mass of table salt (NaCl)?

• 116.886 g/mol
• 35.453 g/mol
• 22.990 g/mol
• 58.443 g/mol

What is the percent composition by mass of sulfur (S) in the compound MgSO₄?

• 20.22%

• 19.85%

• 26.64%

• 28.64%

What is the molar mass of Zn(C₂H₃O₂)₂

• 183.46g/mol

• 169.89L

• 120.65g/mol

• 236.54M

What percent of Zn₃(PO₄)₂ is zinc?

• 33.15%

• 16.04%

• 50.80%

• 19.68%

What is the percent composition of a compound that contains 40.8 g carbon and 54.4 g oxygen?

• 42.9 %; 57.1% oxygen

• 52.9 %; 57.1% oxygen

• 42.9 %; 45.23% oxygen

• 55.9 %; 99.1% oxygen

Find the percent composition of CaCl₂?

• Ca: 36.11%; Cl: 63.88%

• Ca: 53.12%; Cl: 100%

• Ca: 36.11%; Cl: 83.56%

• Ca: 46.11%; Cl: 63.88%

An empirical formula:

• is a formula that calculates the coefficients of a compound in a balanced equation.
• is the simplest whole-number ratio of moles of elements in the compound.

What is the empirical formula of the following molecular formula:  C₃H₆

• C₃H₆
• CH₂
• C₂H₄
• CH₃