Oxidation-Reduction Review

1)    What does the acronym OIL RIG stand for?  Explain what that means.

 

 

2)    For each of the following redox reactions, show how many electrons are added, & on which side, and indicate whether oxidation or reduction has occurred.

 

a.         Ca²⁺  ?  Ca                     _____________________

 

b.         O^2-  ?   O₂                        _____________________

 

c.         Pb⁺²  ?   Pb⁺⁴      _____________________

 

3)    Is the following a redox reaction?  (You do not need to balance this reaction). 

If no, write “No” and in one sentence say why not. 

If yes, write “Yes” and in one sentence say how you know that.

 

SO₂  +  H₂O  ?  H₂SO₄ 

 

 

 

4)    Consider the following reaction, and write the oxidation & reduction half reactions, and identify the oxidizing and reducing agents:

 

Ni⁺²_(aq)  +  Cu_(s)  ?  Cu⁺²_(aq)  +  Ni_(s) 

 

oxidation:

 

reduction:

 

oxidizing agent:

reducing agent:

 

5)    Would the electrolysis of water be spontaneous or non-spontaneous?

 

 

6)    Write an equation illustrating that corrosion is an example of a redox reaction.  Show oxidation numbers for all atoms, stating which elements were oxidized and reduced.

 

 

_____________ was oxidized.            _____________ was reduced.

 

7)    Write an equation illustrating that combustion is a redox reaction.  Show oxidation numbers for all atoms, stating which elements were oxidized and reduced.

 

 

_____________ was oxidized.            _____________ was reduced.

 

8)    For the following diagram showing an electrochemical cell, correctly label:  

1. the direction of electron flow
2. the direction of cation flow across the salt bridge

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Which metal bar is the anode?     ______________________

Which electrode (metal bar) is getting larger?     ______________________

What is happening to the concentration of copper ions?     _______________________________

Why do cations move in the direction you indicated above?

 

 

 

9)    Would an electrochemical cell (such as a battery) be spontaneous or non-spontaneous? 

 

 

 

10) Electroplating is an example of electrolysis.  Suppose you were goldplating a quarter (made from copper and zinc.  The quarter, suspended in the gold (II) nitrate solution, quickly becomes plated with gold.  Would the quarter be the anode or cathode?  Briefly explain how you know.