Conductivity lab

Purpose: To observe the conductivity of different solutions. 

Procedure:

With a measuring spoon place 2 mL of sucrose in the 150 mL beaker. Add 60 mL of distilled water and stir with the graduated pipet. The solution should be about 0.1 M sucrose. Using the pipet put 5 drops into well A1. Put 5 drops of the other materials, KOH, CH, COOH, Cu(NO), glycerin, and distilled water, into the following wells on row A. When they are all filled, attach the 9-volt battery to the conductivity apparatus. Touch the electrodes to a metal object (coin or other) to demonstrate how it acts at maximum conductivity and brightness. Dip both electrodes of the conductivity tester in the solution in well A1 making sure the electrodes do not touch each other. Observe the brightness of the LED, recording the conductivity. Between solutions wash the electrodes using distilled water. Continue testing the solutions in order from A2. 

1. How does conductivity relate to bonding?

Conductivity depends on how well ions bond in certain substances. The more electron pairs there are, the stronger they bond.  

2. Glass is covalently bonded. Are the electrons free to move? How is this related to the conductivity of glass?

Glass is a poor conductor because the electrons are not free to move. 

Below, you will find tips for carrying out the lab.

• 1 scoop is 1ml, so use 2 scoops for step 1 of the procedure
• 5 drops is not enough to place in the wells, the probe will not reach. Fill up the well.
• Make sure to dispose of the copper nitrate using the paper towel and ziptop bag method.  Pipet out of the well and onto the paper towel in the bag.  Seal and dispose of in the trash.
• Wash the 96 well tray immediately after use.  Use a final distilled water rinse.  Invert over a paper towel, tap and allow to dry.
• Label a piece of paper with your lane assignments and place that underneath the tray

Results table: