Name
Date of experiment
Expt 1 melting point analysis
Purpose: To use melting point analysis for the determination of a pure unknown
Procedure: As in Chem 230 lab manual, Camosun College, Revised July 2008 by Dr. Nasr
Khalifa, pages 1-4.
Eg. Unknown A has mpt 120-122oC
Mix unknown A with Mandelic acid
Mix unknown A with Benzoic acid.
Mix unknown A with 2-napthol.
Aside (see page 2 for mp)
Data and results (tabuluar)
Table 1 Melting point of organic compounds
Compound
Mpt oC lab
Mpt oC lit1
Urea
Cinnamic acid
Unknown (LETTER)
Structure
Table 2 Determination of the unknown (LETTER)
Compound mix with Unknown
Mandelic acid
Benzoic acid
2- napthol
Mpt oC lab
Structure
Discussion (theory) Theory: The melting point of pure compounds are narrow and sharp. This
will be lower with a wider range with the presence of impurities. By first determining the
melting point of a pure unknown and then mixing it with a known compound with fairly similar
melting points, the identity of the unknown can be determined. The melting point with a narrow
and sharp range will be that of the pure compound. Refer to tables created in report (ie, Table 1
summarizes the melting point of different organic compounds).
Answer questions page 4
Conclusion Unknown Letter has.,..
References
1. R.Raap, N.Khalifa. Organic Chemistry Experiments for Chemistry 230 and 231.
Camosun College, Department of Chemistry and Geoscience, Victoria, BC, Revised
July 2005. pages 43-45.
2. Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/. Accessed May 15,
2008.
3. McMurry, J. Organic Chemistry, 7th ed.: Brooks Cole, 2008.