NAME                                                                           SECTION LETTER        DATE

 

CHM 235L – INTRODUCTORY EXERCISE

 

1. In general chemistry much of the focus was on ionic compounds. The focus of this lab is on covalently bonded molecules and how they interact and are made. The polarity of molecules affects these interactions and so synthesis and purification. List some of the forces between molecules that you studied in general chemistry and give examples of these interactions. Indicate the stronger and weaker ones and the importance of polarity.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2.  Find the limiting reagent and calculate the theoretical and percent yield for the product in the following reaction. Show your work using unit cancellation (dimensional analysis):

 

                        HC2H3O2            +          C5H12O              ®           C7H14O2           +          H2O

Volume:              31.26 mL                       30.72 mL                        10.73 mL

MW (g/mol):        60.05                            88.15                            130.18

Density(g/mL):    1.053                            0.813                             0.879

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3.  What would the final molarity be of NaOH be if 10.00 mL of 0.300 M NaOH was diluted to 100.0 mL? Show your work using unit cancellation (dimensional analysis).

 

 

 

 

 

 

4. What is a MSDS?  What Information does it provide? (If you can’t answer these questions see #8 below)

 

 

 

 

 

 

5. Get the MSDS from the internet for a compound used in the melting point experiment which starts with the same or closest to the first letter in your last name.  Attach the MSDS to this sheet.

            a.  Name of Compound                                                                        

            b.  Melting Point                                    Boiling Point                            

            c.  Chemical Hazards                                                                

                                                                                                           

            d.  First Aid in Case of Contact                                                 

                                                                                                           

 

6. Using the Baker Hazard Code the flammability rating is based on_______________________.

            Define this term:

 

 

7. Why is a mixed melting point useful?

 

 

 

 

 

 

8.  Next go to the following location or URL on the web using internet explorer if possible (some links will only work in IE) and bookmark the site:

http://jan.ucc.nau.edu/~jkn/Labs.html

 

 

See what information is in the CHM 230L/235L site by clicking on this link and bookmark it (make it a favorite). There are many links on this site. Please take some time to look at them now.

a.     At the top of this page are links for the syllabus, this exercise, lab notebook grading sheets, safety and MSDS source, and a link to check your grades for this lab.

b.    Below this the lab manual is provided online in the first column under “Full Experiment Write-ups”. Make sure you read the “Lab Manual Introduction” and “Experiment 1 – Melting Point” and do the pre-lab question at the end of the experiment before next week.

c.     In the middle column under “Step-By-Step Procedure” there are visual procedures listed in a slide format for each experiment with lots of diagrams that you will find very useful.

d.    In the right hand column these slides are summarized on one or two pages. You will want to print these along with the parts of the experimental write-ups to refer to in lab.

e.     Towards the bottom are links for the appendix and distillation slide presentations. Please look at these also. The “Appendix of Techniques”  has lots of info on techniques used in this course.

f.     Next, click on the “Safety and MSDS Source” link and investigate the types of information available on this web site. Click on "Quiz" and take the on-line tutorial/safety quiz. Complete the entire quiz and print the "Certificate of Achievement" with you name filled in. If you have done this in the past year and the chemistry department has your certificate on file, you don’t have to repeat the quiz.

 

Turn in the "Certificate of Achievement" to your TA before you leave or at the start of the second lab period.