Wednesday, March 2

We started class by picking scribes. Mr. H also figured out that Grace ditched yesterday to avoid being the scribe. Afterwards, he went on to review yesterday's material by going over Mathein's blog.

After all the reviewing, we studied page 9 and the packet we received on Tuesday. He showed us the bond angles of the different joined atoms. He told us that a linear can only have a 180° angles, a trigonal planar can only have 120° angles, and a tetrahedral can only have 109.5° angles. Trigonal Bipyramidals, however, were different. They could have any combinations of 90°, 120° and 180°. After explaining the angle bonds, we moved on to the packets for some practice. We worked on numbers 5, 7, 9, 16, and 17. To help us on these problems and our future webassigns, Mr.H recommended that we look at page 9 in our packets and pg177+181 in our book.

For number 5 we were required to figure out the information of the compound SF4. The lewis dot diagram looks like the diagram on the right. To figure out the number electron groups we looked at the central atom. Sulfur had a total of 5 electron groups because it made 4 singles bonds and had a pair of non bonding pairs. Because it had 4 bonding pairs and 1 non-bonding pair it was a trigonal bipyramidal. Its molecular geometry was a seesaw and had bond angles of 90°, 120°, and 180°. We then continued to work on problems 7, 9, 16, and 17. The answers are...

7) PH3= 4 electron groups, 3 bonding pairs, 1 non-bonding pair, tetrahedral, trigonal pyramid,109.5°

9) SO3= 3 electron groups, 3 bonding pairs, 0 non-bonding pairs, trigonal planr, trigonal planr, 120°

16) ClO2- = 4 electron groups, 2 bonding pairs, 2 non-bonding pairs, tetrahedral, bent, 109.5°

17) ClF2- = 5 electron groups, 2 bonding pairs, 3 non-bonding pairs, trigonal bipyramidal, linear, 180°