Chemistry - Test Review (Molar Conversions)

How many moles are in 72.9 g of HCl?

• 2.00 moles

• 1.34 moles

• 2.97 moles

• 6.02 x 10²³

Tags

NGSS.HS-PS1-7

What percentage of the total atomic mass of carbon monoxide (CO) is composed of oxygen?

• 29%

• 43%

• 57%

• 73%

How many grams are in 3.01 × 10²⁴ molecules of (NH₄)₂SO₄? (Molar Mass (NH₄)₂SO₄ = 132.17 g/mol

• 330.28 g

• 496.81 g

• 660.85 g

• 872.16 g

How many grams of NaOH do you have to dissolve to make 725 mL of a 2.5 M solution?

• 48.4 g

• 18.2 g

• 72.5 g

• 31.9 g

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
• C₃H₈O₃

Tags

NGSS.HS-PS1-7

A sample of the black mineral hematite, an oxide of iron found in many iron ores, contains 34.97 g of iron and 15.03 g of oxygen. What is the empirical formula of hematite?

• FeO

• Fe₂O₃

• Fe₂O₂

• Fe₂O₅

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

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN