Quiz | Review | ions

At the start of class Mrs. Mandarino stamped the homework pg. 11.

Then we reviewed Lewis structure

Example:

H2O

2 x 2e- = 4e-

1 x 8e- = + 8e-

12e- Needed

Minus the total of Valence e- 8e- Total Valence e-

4e- Shared

--------.. ---------- -Has 2 single bonds with equal 4 valence e-
[ H - O - H ] -Has 4 Dots to fill in the ammount of valence
------- `` --------- e- needed.

Next we took the first quiz of our series of quizzes.

Then we went over Covalent ionic bonds.

example:

PO4(3-)

Step 1:

Count the # of atoms total. In the case its 5. 1 P + 4 O = 5.

Step 2:

Take the total # of atoms and times that by 8. This will equal the amount of Valence e- needed

5 x 8 = 40 Valence e- needed

Step 3:

Count the total number of Valence e- for both atoms.

P = 5 valence e- O4 = 24 valence e-

Step 4:

Add the valence e-. [P] 5 + [O4] 24 = 29.

Step 5:

In order to follow the octav rule you must add the 3- e- to the total number of valence e-

29 total Valence e- + 3- = 32 valence eletrons.

Step 6:

Substract the amount of valence e- needed from the amount of total e-

40 valence e- Needed - 32 Valence e- total = 8.

The total amount equals the amount of valence e- shared.

Your math should look something like this.

5 x 8 = 40 Needed

5 + 24 = 29 Total valence e-

29 + 3 = 32 Total valence e- with the 3-

40 - 32 = 8 Shared

The Lewis Structure should look something like this.

------ .. ------

| :O: | 3-

| .. | .. |

| : O - P - O : |

| .. | .. |

| :O: |

| .. |

------ ------|

Ryan G.