Electrochemical Logic Puzzle

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

Quiz Background

Following a lecture on electrochemical cells, a young chemistry student searches his/her home for metal samples for a class project. The student finds five odd shaped pieces of metal in various locations about the house. The metal objects are pure elements, non-uniform in shape, and obviously not identical in composition. The objects were found in the following locations: the backyard, the master bedroom, the basement, the garage, and near the computer in the den. The student correctly assumes that the samples include the following metals: zinc, aluminum, magnesium, silver and tin. The student randomly labels the metal objects A-E and performs some experiments. The experimental results are summarized below.
  • The metal found in the garage forms a +3 ion.
  • The metal found in the backyard has the third most positive reduction potential of the five chosen.
  • Metals A, B, C, and E, all react with dilute hydrochloric acid, metal D does not.
  • The metal by the computer is the least dense of all these metals.

The metal pieces are inserted into a lemon and voltages between the pieces are measured with a digital voltmeter.
  • When the black lead is attached to metal C, and the red lead is connected to each of the other metals, the corresponding voltages are always negative.
  • When the black lead is attached to metal E, and the red lead is connected to each of the other metals individually, A and D are reduced while B and C are oxidized.
  • When the black lead is attached to the metal from the master bedroom and the red lead is attached to the metal from the basement the voltmeter reads +0.9 V.
Determine the correct metal for each label and its original location about the house.
1. The metal found in the backyard is and is labeled .
2. The metal found in the basement is and is labeled .
3. The metal found in the garage is and is labeled .
4. The metal found in the master bedroom is and is labeled .
5. The metal found by the computer in the den is and is labeled .