DCI on Stoichiometry

1. Responses of previous students who were asked to write the balanced chemical equation for Exp #1 in the BCE included;

a) 4R + 4BG --> 4B + 4RG

b) R4 + (BG)4 --> (RG)4 + B4

c) R + BG --> RG + B

d) R4 + BG4 --> RG4 + B4

Identify the best balanced chemical equation for the reaction that occurred in Exp #1, and provide a short explanation. Also provide an explanation for why the other choices were not selected.

 

 

 

 

2. Responses of previous students who were asked to write the balanced chemical equation for Exp #2 in the BCE included;

a) 4R + 2BG --> 2B + 2RG

b) R4 + (BG)2 --> (RG)2 + B2

c) R + BG --> RG + B

d) 4R + 2BG --> 2B + 2RG + 2R

e) R4 + (BG)2 --> (RG)2 + B2 + R2

Identify the best balanced chemical equation for the reaction that occurred in Exp #2, and provide a short explanation. Also provide an explanation for why the other choices were not selected.

 

 

 

3. Responses of previous students who were asked to write the balanced chemical equation for Exp #3 in the BCE included;

a) 2R + 4BG --> 2B + 2RG

b) R2 + (BG)4 --> (RG)2 + B2

c) R + BG --> RG + B

d) 2R + 4BG --> 2B + 2RG + 2BG

e) R2 + (BG)4 --> (RG)2 + B2 + (BG)2

Identify the best balanced chemical equation for the reaction that occurred in Exp #3, and provide a short explanation. Also provide an explanation for why the other choices were not selected.

 

 

4. Write the balanced chemical equation based on the following new Experiment.

 

5. A reagent in excess is a reactant that is not completely used up in a chemical reaction, a limiting reagent is a reactant that limits the amount of product formed in a chemical reaction. Look back at Table II for Exp#1, #2 and #3 and select from below the statement that best fits the assignment of the excess reagent and the limiting reagent.

In Exp #1:

In Exp #2:

In Exp #3:

 

6. Below are shown the initial and final condition for a new chemical reaction.

 

Complete the Table

 
REACTANTS
REACTANTS
PRODUCTS
PRODUCTS
Exp.
Reactant(1)
Reactant(2)
Product(1)
Product(2)
Formula
--->
Initial Amount
Change Amount
Final Amount

Identify the reactant that is the limiting reagent and the excess reagent.

7. In the reaction describe in the balanced chemical equation,

2SO2(g) + O2(g) --> 2SO3(g)

6 molecules of SO2(g) are mixed with 2 molecules of O2(g). Set up a table similar to Q6 above and determine each of the following;

a) the limiting reagent;

b) the excess reagent;

c) the number of molecules of SO3 formed when the reaction is complete;

d) the number of molecules of SO2 remaining when the reaction is complete;

e) the number of molecules of O2 remaining when the reaction is complete;

Do your work here:

 

 

 

8. In the reaction describe in the balanced chemical equation,

2SO2(g) + O2(g) --> 2SO3(g)

5 moles of SO2(g) are mixed with 2 moles of O2(g). Set up a table similar to Q6 above and determine each of the following;

a) the limiting reagent;

b) the excess reagent;

c) the number of moles of SO3 formed when the reaction is complete;

d) the number of moles of SO2 remaining when the reaction is complete;

e) the number of moles of O2 remaining when the reaction is complete;

Do your work here:

 

NOTE to instructors: Students have not yet been in the situation where they must calculate how much of reactant 1 is required to react with reactant 2, and students may find completing the change row challenging in this particular question.