chemistry Lad

CHEMISTRY 145L SPRING 2018

Lab 2B: Read the Label In this experiment you will be introduced to sources of information relative to chemicals, with particular attention paid to health and safety aspects of chemical handling. You will carry out an in-depth survey of three chemicals. They are fairly common chemicals that are widely used in enormous quantities in this country in various types of manufacturing or industrial processes. Choose three of the following six chemicals:

• Phosphoric Acid • Methanol

• Benzene • Sulfuric Acid

• Sodium Cyanide • Sodium Hydroxide

Procedure:

1. Read the label on each chemical and record the following: If some of the information is not on the label for the chemicals you choose, the information can be found when you do part 2 or part 5.

a. Name of the compound b. Molecular formula of the compound c. CAS number d. Hazards and safety information (summarize)

2. Using the CRC “Handbook of Chemistry and Physics” and/or the “Merck Index”, which are available in the reference book section of the SMU Library or in the CHEM lounge (CRC does not refer to our Copy and Resource Center.), look up each chemical and determine:

a. Its density b. Its solubility in various solvents c. Its boiling and melting points d. Its “LD 50 (Lethal Dose for 50% of population)

3. Using the “Guidebook for Hazardous Materials” (on reserve in the library or online), look up

each chemical and very briefly summarize the handling procedures for a “spill.”

4. Using the “TVLs and BEIs” handbook (on the table in the CHEM lounge), determine the “TWA” (Time Weighted Average), “STEL” (Short Term Exposure Limit) values for each substance. Rank your chemicals from the most hazardous (#1) to the least hazardous (#3).

5. “SDS” = “Safety Data Sheet.” Using an on-line search engine, find a site on the web that has SDS’s for your chemicals. Examine the SDS for each chemical and find any interesting/important “toxicity” or health information as it might relate to exposure to the chemical in the workplace. What information does the SDS give you that the other sources you’ve looked at do not provide?

CHEMISTRY 145L SPRING 2018 6. Chemicals at home:

a. Look around your home, apartment, dorm room, etc. and read the label on some household chemicals, cleaning supplies, and foods.

b. List all the materials you find that contain one or more of your “target” chemicals. c. If you find nothing containing the chemicals, list a few of the “interesting” ingredients in

the substances in your home. This exercise may seem like “busy work,” but the information you gain today and an understanding of the means by which you gain this information will be very useful to you in the future. Also, the successful completion of this lab will probably give you a better idea of what those tanker trucks that you pass on I-5 are carrying (it isn’t all milk and gasoline!). The goal of this exercise is for you to become familiar with the resources listed, so you should obtain the information from the source listed. It will be assumed for the practicum that you can sit down with one of these references and efficiently find the information you are after. Note: The write-up for this lab MUST be written in your lab notebook.