The First Of March

To begin, mr H went over the reading sheet that was assigned the previous day on web assign. The Answers For this are as follows
1.B
2.C
3.B
4.B
5.A
6.C
7.A
8.C
9.A
10.a.2,2
b.3,1
c.2,3
d.3,0
11.a. Bent
b.Trigonal Pyramid
c. Linear
d. Trigonal Planar
12.a. Linear
b. Linear
c. Tetrahedral
d. Bent
13. A
14. C
15. AX2E2



Next, Mr. H went over therules that will assist us while drawing Lewis Dot Diagrams. The rules were:
1. Always count the total number of valence electrons and use that number as the number needed of electrons in the diagram.
2. Hydrogen always forms the duet rule
3. Second row elements C,N,O,F will always satisfy the octet rule.
4.Second row elements Be and B will usually have less than the octet rule
5. 3rd row and heavier elements may exceed the octet rule

These rules assisted us with the drawing of some more dot diagrams.

We first started with the compound SF6. This was the simplest of all of the following compounds. We began by counting the valence electrons of both S and F. We got these from the PT. After counting, we ended up with 48 electrons. Next we drew the skeleton with S in the middle and the 6 F's surrounding it. We then gave all the F atoms 8 electrons and ended up with the right amount of total electrons. But there was one problem, the S atom had 12 electrons. But if we refer to the rules above it is acceptable for the S to have more than 8 electrons because it is in the 3rd row.

The next problem was I3-. This was a relatively easy problem after being informed on a new piece of info. When you end up with a ion. You must add electrons if it is a negative ion and subtract electrons if it is positive.

We next did the following problems, BCl3, CN-, O3 and NO3. They all behaved in similar ways and according to the rules above.

After this Semi-review we moved onto the new material for the day. This brought u sthe the Valence Shell Electron Pair Repulsion Theory or more appropriately named the "VESPR".
This chart described how electrons arranged themselves in a compound. The Chart above is the arrangement of the electrons in different arrangements. On page 9 of your paquete you can see a chart containing the corresponding geometry of the pair to the number of electrons in the pairs. After examining this table, we moved onto doing some problems in the mini-paquete that Mr. H gave us. we did the first 3 problems.

For CH4 we began by drawing the Dot Structure of the atom. If you cant do this refer to previous blogs and above. Then we used the diagram to count the number of electron groups which were the number of groups of atoms that were surrounding the central atom. Then we counted the number of bonding pairs. The bonding pairs were counted generally by the number of bonds that were in the diagram. For this problem we got 4 for both the number f groups and the number of bonding pairs. Then we went back to page 9 in the paquete and looked for the corresponding geometry with the table. We found that it was a tetrahedral.

Then we proceeded with the next 2 problems which were the same as the first.

That was the end of the class. YAY