CHEM 2204

Chemical Laboratory Techniques

Browsing Posts published in January, 2016

Your set rep came to pick up your marked Practice graphs on Monday. Some of you did not do a Peer Review of a fellow student’s graph. I encourage you to practice doing Practice Reviews as many of you benefited from the errors that your reviewer spotted and made the corrections before handing the final graph in for marking.

There were some things that were not done properly.

  1. Ensure that you and your peer reviewer(s) sign the graphs that you are handing in
  2. Ensure that you hand in Graph 1 (original graph), Graph 2 (peer reviewed graph), Graph 3 (final graph that I mark)

When you see your marked lab, you will see two marks, which add to a total of 10.

  1. Graph mark: marked out of 8
  2. Peer review mark: marked out of 2

If you did not get 8 out of 8 on the graph mark, you have the option to get up to 1 mark by doing the corrections on your graph. The corrected graph will be due the following week. The corrected graph must be stapled with the marked graphs as I will need to compare it to the previous graphs.

If your determination of the mass of the sand in the vial was +/- 0.006 g ( +/- 0.2%), good job, you did well. Most of you noticed that there were fine sand particles adhering to the side of the vial. In order to determine the mass of the sand accurately, here are the steps to consider.

1. Weigh vial with the sand on the balance.
2. Empty the sand into another container.
3. Rinse the vial with water thoroughly.
4. Dry the vial thoroughly.
5. Reweigh the empty vial.
6. Subtract the mass from step 5 from step 1 to get the mass of the sand.

It is not always necessary to transfer the sand into a weigh boat in order to determine its mass. Leaving the sand in the vial will eliminate the loss of sand during the transfer.

Now that you know how to weigh properly, you need to apply the techniques learned for next week’s lab because next week is all about weighing.

Review the grading of the graphs.
Signatures must appear on the cover page


It is very important that you come to this Friday’s lab well-prepared.

  • Come to the lab on time
  • Have your lab coat, goggles, lab manual and the datasheets, pen, and calculator
  • Prepare and have read Lab 1 – Moisture and Ashing

If you fail to bring any of the above items you will not be allowed to do the lab!

Go to the link below

and download the Friday AM and Friday PM schedules for Lab 1 – Moisture and Ashing. Check the equipment photos as well. We will be following the schedule very closely in order to maximum the drying time of the sawdust samples and the ashing time of our coal samples.

All graphs should be accompanied by a cover sheet.

  • Cover sheet should include:
    Student Name: ___________________
    Peer Reviewer Name:_______________
  • Clearly show which graph is “Graph 1” (the original graph), “Graph 2” (the peer reviewed graph) and “Graph 3” (the corrected graph, if necessary).