Wednesday, April 8, 2009

Lecture #5 Wednesday, April 8th

Lecture started today continuing with the common ion effect and I performed a few calculations illustrating this effect. I talked into more detail about pH effects and reviewed the strong acids and bases. You will need to know the strong acids and bases so MEMORIZE THEM NOW!!! If you can't differentiate between a strong/weak acid or base you will be royally screwed with the problems involving adding reagents to see if they will increase or decrease the solubility.

It is very common for students to have trouble with problems like #31 in the Chapter 17 homework set. The first thing you should do for this problem is WRITE OUT THE EQUILIBRIUM EXPRESSION! I cannot emphasize that more. Application of LeChatlier's principle will then allow you to determine how the solubility will be affected by whatever reagent you choose.

The last topic we covered today was complex ion formation and I listed a few examples and given a Kf table you should, at this point, be able to determine if a complex ion will form. The complex ion effect has much more of an influence on the solubility than the common ion or pH effects.

For homework read Section 17.5 in the textbook and do the following problems from the Chapter 17 homework set: 31-44. (Note: You are falling behind if you have not completed problems 1-30.)

Keep the mailbag comments coming and e-mail me if you have any questions/concerns. Thanks, Dr. Fus

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