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Chem 230 Practicals

This page was last updated on 18-Apr-15

How to write up a practical

Practical for Friday 20th March 2015

Isolation of eugenol from cloves

Read what clove oil contains: https://www.ncsu.edu/bioresources/BioRes_02/BioRes_02_2_265_269_Alma_ENK_CloveOil_Turkish.pdf

Background: Steam distillation

Calculation of the percentage by mass of eugenol in the distillate

You will need these figures to calculate the proportion:

Molar mass of eugenol: 164 g mol-1

Boiling point of eugenol: 225ēC

My estimate of boiling point of a eugenol/water mixture: 99.8ēC  (Measure the actual temperature of the distilling vapour during the experiment.)

Vapour pressure of water at 99.8ēC = 757.2 mmHg  (You should estimate the vapour pressure of water at the boiling point of mixture using internet resources.)

Vapour pressure of eugenol at boiling point of mixture = Atmospheric pressure - vapour pressure of water at boiling point. 

Practical #1

Each group is required to submit a complete write-up of the experiment as follows:

Title - incorporating the aim of the experiment.  Don't use the same title as in the schedule.

Apparatus & Materials - This is the place to put a diagram.  I picture might do if it is easily comprehensible, but it must include labels and a caption.

Method - this is where you relate what you actually did.  Instructions such as, "Mount the thermometer in the clamp." are not acceptable.  You need to say, for example, "The thermometer was mounted in the clamp."  Use your own words.

Results and Conclusions - this is where you record your melting points and melting point ranges.  In this experiment it is probably best to combine these two sections into one.  Your conclusions will include the accurate melting points and remarks as to the purity of the sample, as well as the suitability of the method in certain cases.  In other words, do what it tells you in the book. 

Answers to questions - answer the questions in your practical book. 

Practical #3

Experiment3.pdf - last updated 11:06 am 12 Feb 2015

Practical #4

Here it is: the lab schedule for Friday 20th Feb

Some videos to watch

Chirality explained - Lydia Flynn

Stereoisomers explained - Prof Davis

How to assign R or S to a chiral molecule - Lydia Flynn (NB priority is not decided by size, but by atomic number.)

Enantiomers, diatereomers and meso compounds - maybe a little more complicated than it needs to be, but good.  LOL. - Khan Academy