Moles - Part 2

Moles - Part 2

Multiple Choice

What is the percent by mass of sodium in NaCl?

• 39%

• 61%

• 35%

• 65%

Multiple Choice

What is the percent by mass of oxygen in MgO?

• 20%

• 40%

• 50%

• 60%

Multiple Choice

A compound is a hydrate when it...

• is composed of only hydrogen and oxygen

• is a state of water

• traps water inside of the compound

• repels water from the compound

Multiple Choice

How many moles are present in 32.3 grams of carbon dioxide (CO₂)?

• 44.01 moles

• 1421.52 moles

• 32.3 moles

• 0.73 moles

Multiple Choice

What is the definition of molar mass?

• 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

Multiple Choice

How many moles are in 225g of CO?

• 8.03 mole

• 28.01 mole

• 4.82x10²⁴ mole

• 7.50 mole

Multiple Choice

C₂F₆

Choose the correct empirical formula...

• CF

• C₂F₆

• C₆F₂

• CF₃

Multiple Choice

What is the empirical formula for C₄H₆?

• CH

• CH₃

• C₂H₃

• C₄H₆

Multiple Choice

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

Multiple Choice

A formula with the lowest whole # ratio of elements in a compound is called

• Molecular Formula

• Chemical Formula

• Empirical Formula

• Distance Formula

Multiple Choice

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

• Mg₄N₃

• MgN₂

• Mg₃N₂

• MgN

Multiple Choice

Determine the formula of CuSO₄·?H₂O hydrate given the following data:

Test Tube = 23.56 g

Test Tube + Hydrate = 26.06 g

Test Tube + Anhydrate = 25.16 g

• CuSO₄·H₂O

• CuSO₄·2H₂O

• CuSO₄·4H₂O

• CuSO₄·5H₂O

Multiple Choice

A 15.67 g sample of a hydrate of magnesium carbonate was heated to drive off the water. The mass was reduced to 7.58 g. What is the formula of the hydrate?

• MgCO₃ · 5H₂O

• MgCO₃ · 4H₂O

• MgCO₃ · 6H₂O

• MgCO₃ · 1H₂O

Multiple Choice

A hydrate of magnesium chloride is present and the following data is collected:

mass of crucible = 22.130 grams

mass of crucible + hydrate = 25.290 grams

mass of crucible and contents after heating = 23.491 grams

What is the complete formula of this hydrate?

• MgCl₂ · 7H₂O

• MgCl₂ · 11H₂O

• MgCl₂ · 6H₂O

• MgCl₂ · 13H₂O