Experiment 16 (Part 1)

Hi everyone,

I hope you had a good weekend.

This lab was quite a long one. Here are the tips that might help you:

- Reminder: This week they hand in their reports at the end of the lab (that's why it takes longer than usual)

- They have to make an agar gel and wait for it to cool down. A good way for saving time is to tell them to get started right away and then give the prelab talk while they're waiting for the gel to solidify

- Walk around and make sure they have figured out the electrodes correctly. There is a very helpful chart beside every board that can be used:

Cu: orangish color, Zn: has a punched hole on it, Ag: not as flexible as Cd and Pb, Pb: flexible and soft (you can scratch it with your nail), Cd: also flexible and soft but not as much as Pb

- If they read zero while measuring a cell tell them to reverse the clips

- Some electrodes develop a black precipitate while reacting. Tell them to sand it off before every measurement if such a thing happens between runs.

- Make sure they are doing the second part correctly (determining the Ksp). It is a bit confusing for them. It doesn't hurt to put a scheme on the board of how one would set up the experiment. Also tell them that in this part they should use the same electrode for both half-calls, same as the cation (for example, measuring AgCl one uses Ag electrodes)

That's all for this week!

 

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This page contains a single entry by sohra004 published on April 18, 2011 4:17 PM.

Experiment 15 (week 2) was the previous entry in this blog.

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