Standard Chemistry - Electrochemistry Test

  1. Label the oxidation numbers in each of the following compounds and ions:

    2. SO4-2 KMnO4 NCl3 H2O2

  2. Draw the galvanic cell that could be made form the following reaction and calculate the voltage on the cell.

    3. Cr2O7-2 + Mg ® Mg+2 + Cr+3

    Be sure to:

    label all parts including the cathode and anode

    tell me what is in each beaker

    what each wire is made of

    What direction the electrons flow

    What direction the ions in the salt bridge flow

    Which side is the anode, and which is the cathode

  3. Do either a or b:
  1. balance the following reactions

H2O2 + Cu+1 ---> Cu+2 + H2O

 H2O2 + Si ---> SiO2 + H2O (basic)

AuCl3 ® Au + Cl2

Bi2O3 +OCl- ---> BiO3- + Cl- (basic)

Sb2O3 + IO3- + Cl- ---> Sb(OH)6- + ICl (basic)

MnO4- + Fe+2 ---> Fe+3 + Mn+2

b) briefly answer all of the following questions:

In class we discussed two dangerous things about car batteries. Tell me about them (what the dangers are and how/why they can occur)

What makes a battery rechargeable?

What is the purpose of the paper (porous separator) in a regular cell (like a D "battery")

What is the difference between a cell and a battery?

What are the three purposes of electrolysis?

Draw the set-up used to gold plate a spoon. What are the reactions that occur?

Why do each of the following protect iron from rusting: wax, paint, zinc

Why is it better to make a car out of aluminum than iron?