Download Lab 8-VSEPR 1

Chemistry 161
Lab 8 - VSEPR - 1
Prelab Questions:
(1) Draw the Lewis structures of the following compounds:
(a) GeH4 (b) PH3 (c) H2Se (d) AsCl5
(e) ClF3 (f) XeF2 (g) SF6 (h) BrF5
(2) What does the word “VSEPR” stand for?
Objective:
In this lab you will study molecular geometry using VSEPR.
Procedure:
At the beginning of the lab you will be given a summary sheet that includes a list of molecules. You will
have to draw their Lewis structures.
You will use your Lewis structures to build your molecules using both the computer program and the balland-stick model. The Instructions about the use of the computer program and the set of ball-and-stick
model will be provided at the beginning of the lab.
Your task will be to fill out your summary sheet based on the results of your activities.
Questions :
(1) Explain why a lone pair of electrons might take up more space than the bonding pair.
(2) If you are using the ball-and-stick model, what does each ‘ball’ represent? Each “stick”?
(3) Draw the Lewis structure of O3 with a O-O-O backbone and with a cyclic backbone (three oxygen
atoms in a ring). Discuss VSEPR of both structures. Discuss the bond angles. Can you tell which
structure is more stable?
Postlab:
Your summary sheet has to be filled out and taped to the notebook. The postlab will also include the
answers to the questions.