Concordia College

Chem 127L Laboratory Homepage

The end is in sight as we move towards the end of the semester and this time we are moving away from the bulk physical properties of a chemical or a mixture of chemicals in regards such concepts as pH, color or density but rather thinking about the physical shape of individual molecules. Why? Well molecular shape plays a large role in determining properties of a molecule over and above that arising from just atoms which make the molecule up.  Orientation of polar bonds, net dipole moments and a number of other properties arise from the shape of a molecule and this is key in properties such as bonding and reactivity so this experiment considers molecular shape as determined by VSEPR and then what symmetry elements the molecule possesses.

The lab is slightly abbreviated from the version in the lab manual as the hyperchem portion has been dropped. This means the lab consists of simply going station to station and working out molecular shape, drawing Lewis Electron dot structures and determining symmetry elements for each molecule.

Key Concepts:

Electron counting and molecular shape as determined by VSEPR

Drawing both Lewis electron dot structures and three dimensional shapes of the molecules

Identifying the three stated symmetry elements and which are present in the molecules.

Important Documents:

Lab Syllabus

Lab Schedule (one page)

Lab Safety Sheet

Report Writing /Keeping a Good Lab Notebook

Formal Report Guidelines (Coming Soon)

Lab Make-up Information:

You are required to complete all the experiments as part of the 127L lab course. However, due to reasons of illness, scheduling conflicts etc, sometimes you will miss a lab. To schedule a time to carry out the lab, you should contact Dr Wyllie as soon as possible. If you know in advance you are missing a lab, let Dr Wyllie know the week before, if you miss the lab itself such as for illness, contact Dr Wyllie as soon as you can.

Unless there are exceptional circumstances, labs must be made up the same week they are missed. The regular lab times are listed below and you should try to make up the lab in one of these, if these times do not work, include this information when you contact Dr Wyllie.

The procedure for making up a missed lab is given below, if this is not followed, you will not get the credit for the lab you make-up.

Email the following information to Dr Wyllie (wyllie@cord.edu)

Name:

Lab Section (Time / Instructor):

Experiment to be Made-up:

When you plan to make it up:

Dr Wyllie will then email you a confirmation and you should attend the stated section for the make-up. In the lab, there will be a form you will get from the TA with the above information which you will attach to your entrance and exit quizzes and have signed by the instructor at the end of the lab. This is left in the lab to be collected and distributed to your instructor by Dr Wyllie. If you do not have this form, you will not be credited for the lab. You cannot just turn up to any lab for making up an experiment, we have a very large class this year so we have to manage resources and lab space. In addition, it allows better tracking of lab make-ups so you can be sure your grade is being credited for the lab.

Instructors

Lab Sessions

Lab Schedule:

Dr Graeme R. A. Wyllie
wyllie@cord.edu
(218)-299-4956