Moles Review

What is the molar mass of NaCl?

• 58.45g/mol
• 28g/mol
• 12g/mol
• 6.02 x 10²³

What would be the mass of 1.5mol H₂O

• 20
• 27
• 32
• 40

Tags

NGSS.HS-PS1-7

What is the percent by mass of fluorine in CaF₂ (gram-formula mass = 78 g/mol)?

• 24%
• 49%
• 51%
• 65%

Tags

NGSS.HS-PS1-7

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%

How many moles of carbon atoms are there in 5g of carbon?

• 60 mol
• 17 mol
• 0.42 mol
• 7 mol

How many moles are there in 12.7g of CaF₂?

• 0.20 mol
• 1,000.76 mol
• 6.14 mol
• 0.16 mol

Tags

NGSS.HS-PS1-7

What is the mass of 9.4 moles of B₂(Cr₂O₇)₃?

• 6.41 x 10²²g
• 5.67x10²⁴ g
• 49.11 g
• 6294.005g

A compound consists of 72.2% magnesium(Mg) and 27.8% nitrogen(N) by mass. What is the empirical formula?

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements.

• SO
• SO2
• SO3
• SO4

Glycerol has a molar mass of 92.09g/mol. Its percent composition is: 39.12% C, 8.75% H, and 51.12% O. What is the molecular formula for glycerol?

• C₂H₃O₂
• CH₂O
• C₂H₄O₂
• C₃H₉O₃