Stoichiometry Review

2 NaClO₃ (s) --> 2NaCl (s) +3 O₂ (g)  
12.00 moles of NaClO₃ will produce how many grams of O₂?

• 256 g of O₂
• 576 g of O₂
• 288 g O₂

Tags

NGSS.HS-PS1-7

In a lab, a scientist calculates that he should produce 12.3 grams of product in his experiment. When he is finished collecting his product, it weighs 10.1 grams. What is his percent yield?

• 82%
• 0.82%
• 10.1 %
• 100%

Tags

NGSS.HS-PS1-7

4 Al + 3 O₂ –> 2 Al₂O₃  How many moles of aluminum would be needed to completely react with 45 grams of O₂?

• 1.05 moles
• 3.75 moles
• 1.875 grams
• 1.875 moles

Tags

NGSS.HS-PS1-7

If a chemist calculates the maximum amount of product that could be obtained in a chemical reaction, he or she is calculating the

• theoretical yield
• mole ratio
• actual yield
• percentage yield

Mole ratios are obtained from the

• balanced chemical equation
• periodic table
• molar mass

Tags

NGSS.HS-PS1-7

When does a chemical reaction stop?

• When the lab is finished
• When the excess reactant is used up
• When the limiting reactant is used up
• Chemical reactions never stop

Tags

NGSS.HS-PS1-7

Balance the following reaction :
 
CaC₂(s)   +   H₂O(l)   -->   C₂H₂(g)   +   Ca(OH)₂(aq)

• 1,2,2,2
• 1,2,1,1
• 2,1,1,1
• 2,1,2,1

Fe (s) + S (l) --> FeS (s)  

In the experiment above, 7.62 g of Fe are allowed to react with 8.67 g of S.
How much FeS is formed?

• 14.8 g
• 12.2 g
• 13.7 g
• 9.9 g

Tags

NGSS.HS-PS1-7

What is a Limiting Reagent?

• speeds up a reaction
• what you run out of first
• what you have left over
• slows down a reaction

Tags

NGSS.HS-PS1-7

What is a Excess Reagent?

• amount you end with
• what you run out of first
• what you have left over
• what you start with