Unit 9 Practice Test - Stoichiometry

What is the difference between the theoretical yield and the actual yield for a reaction? (Choose all that apply)

• The theoretical yield is calculated

• That actual yield is calculated

• The theoretical yield is determined in the lab

• The actual yield is determined in the lab

Theoretical yield = 73g
Actual yield = 62g
Calculate the percent yield.

• 1.16%
• 116%
• 85%
• 76%

How much of the limiting reactant is used in a reaction?

• None of the reactant

• Half of the reactant

• All of the reactant

• It depends

What best describes the excess reactant?

• Some of it will be left over after the reaction stops

• The reactant used up entirely

• The reactant that limits the amount of products made

• The reactant that produces the least amount of product

N₂ +  3H₂ → 2NH₃ 
What is the mole ratio for Nitrogen (N₂ ) to Ammonium (NH₃) in the above reaction?

• 1:2 

• 2:1

• 2:3

• 1:3

N₂ +  3H₂ → 2NH₃ 
What is the mole ratio for Nitrogen (N₂ ) to Hydrogen (H₂) in the above reaction?

• 1:2 

• 2:1

• 2:3

• 1:3

2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O

How many moles of ethane (C₂H₆) are required to produce 12 moles of water from the above reaction?

• 4.0 mol C₂H₆

• 2.7 mol C₂H₆

• 40 mol C₂H₆

• 8.1 mol C₂H₆

4NH₃ + 5O₂-->4NO + 6H₂O
How many moles of NH₃ are required to produce 8 moles of H₂O?

• 10 moles NH₃

• 5.3 moles NH₃

• 5.5 moles NH₃

• 4.0 moles NH₃

4NH₃ + 5O₂-->4NO + 6H₂O
How many moles of NH₃ are required to produce 20 grams of H₂O?

• 1.0 moles NH₃

• 0.7 moles NH₃

• 0.5 moles NH₃

• 4.0 moles NH₃

4NH₃ + 5O₂-->4NO + 6H₂O
How many moles of NH₃ are required to produce 20 L of H₂O?

• 1.0 moles NH₃

• 0.6 moles NH₃

• 0.5 moles NH₃

• 4.0 moles NH₃