Last modified: Mon 07/25/2016 05:07:10 pm ACA

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Answer all of the questions below. If you do not know an answer enter CNA. However, it will help me the most if you answer each question with your best intuition/idea about what would be a reasonable answer.


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1. Identify four variables that effect the mass of the metal plated out at the cathode when an aqueous solution containing a metal ion is electrolyzed.

Variables that would effect the mass of the metal plated at the cathode

1.

2.

3.

4.

 

2a. How many moles of copper will plate out at the cathode when an aqueous solution of copper (II) nitrate is electrolyzed for 4.00 minutes with a current of 3.5 amps?

moles Cu

b) How many moles of Zn would be plated out if a zinc (II) nitrate solution is electrolyzed for 4.00 minutes with a current of 3.5 amps?

moles Zn

c) How many moles of silver would be plated out if a silver (I) nitrate solution is electrolyzed for 4.00 minutes with a current of 3.5 amps?

moles Ag

3. In Question 2, the cell must be on for 14.5 minutes to plate 1.00 gram of copper at the cathode. Would the same, less, or more time be needed to produce 1 g of silver at the cathode?

Describe the two variables that must be considered to answer this question, and how those variables affect the time.

4. The half-reaction that occurs at the cathode in electrolytic cell described in Q2a above is

Cu2+(aq) + 2e- --> Cu(s)

Briefly describe where the Cu2+(aq) and the electrons (e-) come from.

5. Is there anything about the questions that you feel you do not understand? List your concerns/questions.

6. If there is one question you would like to have answered in lecture, what would that question be?