CHM 100 – Introduction to Chemistry

Laboratory Experiment Changes and/or Comments

Expt. #

Title

Laboratory Expt. Changes / Comments / Tips

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Check in; Safety; Basic Laboratory Techniques

The laboratory instructor will go through the Safety Rules with the students.  Students must then sign the 3^rd page and submit this sheet to their laboratory instructor.  The laboratory instructor retains these signed sheets for the entire semester.

Have students sign up on the “Student Glassware Sign-up Sheet” for a number from 1-18.  The original sign up sheet should be given to either Bob Colando or Bonnie Fong.  We will make a copy to give to the instructor for their records and leave a copy in the lab for students to refer to (if they forget what their number is).

2

Metric System Measurements

Part D:  set up as a DEMO only

Part F:  the unknown refers to the wooden blocks

Part G:  pennies may be substituted for nickels

3

Density of a Liquid and Solid

Part A:  set up as a DEMO only

Part B:  use 5mL instead of 10mL?

Part C:  you may need to explain to the students that the same unknown samples vials are used again by the next class, so they should be careful not to contaminate them, should only use what they need, and then return the sample vials to the box before they leave the lab

Part D:  use size 00,0,1 rubber stoppers instead of size 2

5

Physical and Chemical Properties

Please click here for the Revised Procedure.

Part B1b:  DEMO – use no more than a few crystals of I₂ (s)

Part B2:  heat the NH₄CO₃ (s) under the fume hood

Extra:  Assign students an element and have them look up information about that element in the CRC

6

Change in State

Lauric acid will be used instead. 

Please click here for the Revised Procedure.

Please click here for instructions on using Microsoft Excel 2003 to graph data.

Instructors:  Sign up for the PETS and laptops in Rm. S-315.  Remember to make use of the “Sign-up sheet for Laptops”.

7

Periodic Classification of the elements

Please click here for the Revised Procedure.

Extra:  Utilize the gas discharge power supply, spectrum tubes, spectroscopes, & Spectral Analysis Chart

8

Structure of Compounds

Molecular model sets are usually on a cart near the front of the lab.

There are NO unknowns for this laboratory experiment.

9

Cation Analysis

There should be 3-4 centrifuges around the lab.  Centrifuge for about 2-5 minutes.

Please have ALL students do the flame tests in the designated spot under the hood.  It is almost impossible to see the green flame for the barium test.

Check that the students’ test tubes are clean at the end of the lab

10

Anion Analysis

There should be 3-4 centrifuges around the lab.  Centrifuge for about 2-5 minutes.

Check that the students’ test tubes are clean at the end of the lab

13

Empirical Formula

Part B:  OMITTED

14

Chemical Reactions

Please click here for the Revised Procedure.

Extra:  Worksheet for Week II

16

Analysis by Precipitation

Please click here for the Revised Procedure.  Please click here for the Revised Data & Calculations sheet. 

NOTE:  Changes to the above-mentioned Revised Procedure and Data & Calculations sheets may be made. 

Instructors will label a tray with their name and class meeting day & time.  Students will then leave their labeled samples on this tray to dry (until the following week).

19

Solutions

Part A (entirely):  set up as an observation only

Part C:  set up as a DEMO only (heat 20g NaCH₃COO & 2mL H₂O in a 125mL flask until all the solid has dissolved…do NOT allow it to boil…when the contents of the flask has cooled to room temperature, add a seed crystal)

Part D:  use 150mL of tap H₂O instead of 200mL of distilled H₂O

Last updated:  January 19, 2006