advanced stoic

1. What is a limiting reagent?

• any reactant used up first in a reaction.
• any reactant left over at the end of a reaction.
• the maximum amount of product formed from a given amount of reactant.
• the purity of the reactant.

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NGSS.HS-PS1-7

1 Cheese + 2 Bread --> 1 Grilled cheese
How many grilled cheeses can you make with 26 slices of bread and 14 pieces of cheese?

• 14
• 13
• 26
• 7

When 12 moles of O₂ reacts with 6 moles of C₁₀H₈, what is the limiting reactant?  
1 C₁₀H₈ + 12 O₂ --> 10 CO₂ + 4 H₂O

• Oxygen
• C₁₀H₈
• Water
• Carbon Dioxide

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NGSS.HS-PS1-7

Use the equation 2 Al + 3 Cl₂ ---> 2 AlCl₃.  If 2 moles of aluminum and 2 moles of chlorine are reacted, identify the limiting reactant.

• AlCl₃
• Cl₂
• Al
• None

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NGSS.HS-PS1-7

6. What is theoretical yield?

• the maximum amount of product that could be formed from a given amount of reactant.
• the amount of product that actually forms when a chemical reaction is carried out in a laboratory.
• the efficiency of a particular chemical reaction within the respective conditions.
• the reactant that is used up first in a reaction.

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NGSS.HS-PS1-7

7. The amount of product that actually forms when a chemical reaction is carried out in a laboratory is called the _________ yield.

• actual
• theoretical
• percent

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9. Complete the equation for the percent yield of a chemical reaction:
Percent yield=(________)÷(________)×100%

• actual yield; theoretical yield
• theoretical yield; actual yield

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NGSS.HS-PS1-7

11.
LiOH + KCl → LiCl + KOH    
a)  I began this reaction with 20 grams of lithium hydroxide.  What is my theoretical yield of lithium chloride? 

• 35.5 grams
• 11.3 grams
• 0.03 grams
• 0.09 grams

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NGSS.HS-PS1-7

12.
C₃H₈ + 5 O₂ →3 CO₂ + 4 H₂O 
b)  I got a percent yield of 75%, and I started with 5 grams of C₃H_8. How many grams of water did I make?

• 6.2 grams
• 1.5 grams
• 8.3 grams
• 4.2 grams

13.
Be + 2 HCl → BeCl₂ + H₂    
My theoretical yield of beryllium chloride was 10.7 grams.  If my actual yield was 4.5 grams, what was my percent yield? 

• 42.1 %
• 2.38 %
• 1.24 %
• 27.2 %

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NGSS.HS-PS1-7