SYNT 0719 – Brominating Alkenes
SYNT 0719 – Brominating Alkenes
OBJECTIVE
The purpose of this lab will be to brominate trans-stilbene by using acetic acid and pyrimidium tribromide by refluxing the mixture. To test the purity of product I will take the melting point which should be around 240 ºC along with a flame test which should be green-blue.
CHEMICAL PROPERTIES TABLE
See Attached Lab Notebook Copies
REACTION MECHANISM In this lab we used multiple techniques to complete and verify the bromination of trans-stilbene. First technique we used was to reflux the mixture; this contains having the mixture boiling so it will evaporate while the condenser will recondense the solvent which is boiling off so the solvent may stay in the reaction. Next we used the melting point of the product to verify which product was produced along with the purity of the compound. Lastly we did a flame test using copper which will change to a green-blue flame in the presence of a halogen.
PROCEDURE, DATA, OBSERVATIONS
See Attached Lab Notebook Copies
RESULTS
Compound or Object
Mass (g)
M.P. Measured (ºC)
M.P. Theoretical
(ºC)
Percent Yield
(%)
Meso-1,2-dibromo-1,2-diphenylethane
0.167
236.9-237.9
238.0
Trans-stilbene
0.105
Pyridinium acid
0.203
acetic acid
2.0 mL
Filter paper
0.073
Watchglass
57.252
Flame Test w/ copper only
Orange
Flame Test w/ copper & product
Green
Percent Yield = (0.167 g) / (g) X 100% =
For this lab I had a percent yield of % for meso-1,2-dibromo-1,2-diphenylethane. I verified this product by my measured melting point range which was within 0.1 of theoretical melting point of 238 ºC and from the flame test, where the flame of the copper with the product turned green showing that a halogen was present.
CONCLUSION
In conclusion, I was successful at brominating trans-stilbene with the use of pyridinium tribromide by using a reflux apparatus. When refluxing the mixture, the color was a yellow-orange while boiling, once I took this off the
OBJECTIVE
The purpose of this lab will be to brominate trans-stilbene by using acetic acid and pyrimidium tribromide by refluxing the mixture. To test the purity of product I will take the melting point which should be around 240 ºC along with a flame test which should be green-blue.
CHEMICAL PROPERTIES TABLE
See Attached Lab Notebook Copies
REACTION MECHANISM In this lab we used multiple techniques to complete and verify the bromination of trans-stilbene. First technique we used was to reflux the mixture; this contains having the mixture boiling so it will evaporate while the condenser will recondense the solvent which is boiling off so the solvent may stay in the reaction. Next we used the melting point of the product to verify which product was produced along with the purity of the compound. Lastly we did a flame test using copper which will change to a green-blue flame in the presence of a halogen.
PROCEDURE, DATA, OBSERVATIONS
See Attached Lab Notebook Copies
RESULTS
Compound or Object
Mass (g)
M.P. Measured (ºC)
M.P. Theoretical
(ºC)
Percent Yield
(%)
Meso-1,2-dibromo-1,2-diphenylethane
0.167
236.9-237.9
238.0
Trans-stilbene
0.105
Pyridinium acid
0.203
acetic acid
2.0 mL
Filter paper
0.073
Watchglass
57.252
Flame Test w/ copper only
Orange
Flame Test w/ copper & product
Green
Percent Yield = (0.167 g) / (g) X 100% =
For this lab I had a percent yield of % for meso-1,2-dibromo-1,2-diphenylethane. I verified this product by my measured melting point range which was within 0.1 of theoretical melting point of 238 ºC and from the flame test, where the flame of the copper with the product turned green showing that a halogen was present.
CONCLUSION
In conclusion, I was successful at brominating trans-stilbene with the use of pyridinium tribromide by using a reflux apparatus. When refluxing the mixture, the color was a yellow-orange while boiling, once I took this off the