Chemistry Chemical Quantities Review

What is the formula mass of CO₂?

• 44 grams
• 44 amu
• 0.44 grams
• 2.6 x 10²⁵ atoms

What is the percent composition of nitrogen in NH₃?

• 25%
• 14%
• 28%
• 82%

Which of the following is an empirical formula?

• C₃H₃
• Li₂CO₃
• Na₂O₂
• C₆H₁₂O₆

How many atoms of sodium are contained in a mole of sodium?

• 6.02 x 10²³ atoms

• 11 atoms

• 23 atoms

• 2 atoms

If the empirical formula is CH and the molar mass of the compound is 78g/mol, what is the molecular formula?

• C₆H₆

• C₅H₁₈

• CH

• 6CH

How many moles are in 16.94g of water?

• 16.94 mol H₂O
• 0.9401 mol H₂O
• 305.3 mol H₂O
• 1.063 mol H₂O

How many grams are in 1.2 x 10²⁴ molecules of CO?

• 28 grams
• 56 grams
• 6.02 grams
• 1.2 grams

What is the percent composition of Benzene, C₆H₆?

• C = 50%
  H = 50%
• C = 85.7 %
  H = 14.3%
• C = 92.2%
  H = 7.8%
• C = 71.9%
  H = 28.1%

What is the definition for Avogadro's number?

• number of grams per one mole of a substance
• whole number ratio that is a multiple of a chemical formula
• simplest, whole number ratio of a chemical formula
• 6.02 x 10^23 particles per one mole of a substance

What is the mass in grams of 5.90 mol C₈H_18?

• .0512 g
• 19.4 g
• 673 g
• 389 g