CRS001

=Researcher= Cuepil Choi

=Objective= To observe the possible products of mixing together 4-chlorobenzaldehyde and ethanol at standard temperature and pressure.

=Prodedure= 1.4220g of ethanol was added to .1137g of benzaldehyde crystals in a small vial. The reagents were mixed together by repipetting the mixture several times. **[explain when and how the NMRs were taken JCB]**

=Results= [|HNMR spectrum after approximately 30 minutes] [|HNMR spectrum after approximately 1 hr] [|HNMR spectrum after approximately 1 hr 30 minutes] Current graphs have a shift of approximately 2.1ppm [|sheet 1](unfinished) =Discussion= The small amounts of (4-chloro?) hemiacetal that was created through the reaction of 4-chlorobenzaldehyde and ethanol was expected. However, comparing the results of this lab to Dr. Bradley's lab with 4-chlorobenzaldehyde and methanol showed a 4-chlorobenzaldehyde to (4-chloro) hemiacetal ratio of 2:1. The drastically different ratios from these two labs may be the result of mechanism differences between the reaction of 4-chlorobenzaldehyde with methanol and the reaction of 4-chlorobenzaldehyde with ethanol. =Conclusion= The system reached equilibrium by the time the first HNMR graph was taken at 30 minutes. All three HNMR graphs were nearly identical, showing that the first HNMR graph showed equilibrium. The mixture at equilibrium contained small amounts of hemiacetal. With a basic estimate using the HNMR graphs without the actual integration values, the approximate ratio of (4-chloro?) hemiacetal : 4-chlorobenzaldehyde : ethanol was 1:10:500.

=Log= 11:38 weight of empty (approx) 3.3mL vial was 4.7488g 11:38 0.1137g of 4-chlorobenzaldehyde was put into the vial 11:39 1.4220g of ethanol was added o the 4-chlorobenzaldehyde 11:40 mixture was repipetted several times, all the 4-chlorobenzaldehyde crystals went in. 12:08 first HNMR spectrum was taken 12:37 second HNMR spectrum was taken 1:37 third HNMR spectrum was taken