• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Dehydration and Gas Chromatography of Methylcyclohexanols.

Extracts from this document...

Introduction

Hurst

Chase A. Hurst

CHM 215 11

Dr. Daniel Ketcha

October 28, 2004

Dehydration and Gas Chromatography of Methylcyclohexanols

Introduction

The experimental confirmation of the “Evelyn Effect” was performed in this report.  This effect, first described by David Todd of Pomona College in 1994, describes the formation of 1-methylcyclohexene and 3-Methylcyclohexene (structures shown below) derived from the dehydration and distillation of a mixture of cis-2-methylcyclohexanol and trans-2-methylcyclohexanol (structures shown below) when reacted with phosphoric acid.  

Figure 1.  Stereochemical Structures of Methylcyclohexanols.

image01.png

image02.png

This reaction was carried out according to the following mechanisms.

Figure 2.  Reaction Mechanism of Dehydration of cis/trans-2-methcylohexanol Mixture.

image08.png

Procedure

150 mmol (≈ 18.419 g) of 2-methylcyclohexanol (cis - trans mixture) was placed into a 50 mL round bottom flask.  Mixed in this flask was 5 mL of 85% phosphoric acid, 3 drops of sulfuric acid (to quicken reaction), and a few acid resistant boiling chips.  A simple apparatus for distillation was assembled and two 10 mL graduated cylinders were used to collect the distillate.

The contents of the 50 mL round bottom flask were gently brought to a boil and the temperature of the vapor was approximately 115 °C.

...read more.

Middle

Figure 3.  Organic Distillate Gas Chromatograms*.

Organic Distillate Sample 1

Organic Distillate Sample 2

image12.jpgimage00.png

image00.pngimage13.jpg

*Arrow indicates 1-methylcyclohexene calculated from standard gas chromatograph of pure 1-methylcyclohexene with retention time of 2.6 minutes.

Table 2.  Organic Distillate Gas Chromatograph Calculations.

Organic Distillate Sample 1 Area and Retention Time Calculations

image14.png

Organic Distillate Sample 1 Total Area

image03.png

% Composition of Constituents in Organic Distillate Sample 1

image04.png

Organic Distillate Sample 2 Area and Retention Time Calculations

image05.png

Organic Distillate Sample 2 Total Area

image06.png

% Composition of Constituents in Organic Distillate Sample 2

image07.png

Table 3.

...read more.

Conclusion

Even accounting for this error, however, it seems unlikely that this jeopardized the validity of the experimental results.  While the product yields were significantly lower than those predicted by Todd the results were significant enough in order to see the appearance of the “Evelyn Effect.”  

Furthermore examining the physical/chemical properties of both 1-methylcyclohexene and 3-methylcyclohexene it is apparent that 1-methylcyclohexene is slightly more stable than 3-methylcyclohexene.  This property can be deduced by examining the boiling points of the two isomers.  The boiling point of 1-methylcyclohexene is 110 °C while the boiling point of 3-methylcyclohexene is slightly lower at 104 °C.  The slightly larger amount of heat energy required to boil 1-methcycyclohexene (6 °C) than 3-methylcyclohexene shows that the latter is slightly more stable.  In this context it becomes apparent that 3-methylcyclohexene is more apt to convert to 1-methylcyclohexene; the more stable of the two isomers.  



[1] Density given in g/mL

a Mixture of cis/trans isomers

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Probability & Statistics section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Probability & Statistics essays

  1. Standard addition was used to accurately quantify for quinine in an unknown urine sample ...

    The fluorescence intensity was then measured and recorded for each solution. Results The results obtained from the experiment were as follows: Fig. 4 A table to show the variation in fluorescence intensity against the volume of standard solution of quinine added.

  2. Used Cars - What main factor that affects the price of a second hand ...

    This will show how strong the correlation between the two factors is. The table below shows the corresponding ranks of each car. Engine size rank Mileage rank age rank Price rank 1.5 39 45 3 1.5 35 25.5 17 4 41 45 2 4 20 13 8 4 4 13

  1. find out if there is a connection between people's IQ and their average KS2 ...

    I calculated the intercept, this will show where my trendline goes through the y axis. =INTERCEPT(M12:M61,L12:L61) My intercept was 54.11 and this means that my trendline will go through the y axis at the IQ mark of 54.11. Together with my slope and intercept I can make the formula for my trendline.

  2. I want to find out if there is a connection between people's IQ and ...

    Plan and Analysis: I wanted to make a new hypothesis so that I could try to eliminate bias in my sample and go into further detail. Bias was a big problem in my last hypothesis, as I had got the sample by picking random numbers.

  1. The Composition of Milk

    * We neutralised the filtrate we had obtained (filtrate 1) with sodium carbonate. We tested the filtrate with universal indicator after each drop of sodium carbonate in order to obtain a neutral solution, which was indicated as green on our universal indicator.

  2. Analyse a set of results and investigate the provided hypothesise.

    I will first select the data from the pool that I will use to analyse. This is not as simple as it sounds though. When selecting data from the pooled set of results we need to take into consideration how many males were asked and how many females were asked, this is called stratified random sampling.

  1. Investigate people's judgement of measurements.

    on average girls will be more accurate than boys because girls tend to be more precise, thoughtful and careful There will be individual anomalies to the above predictions as peoples judgement is a personal attribute and also luck will be a random factor.

  2. Identifying Relationships -Introduction to Statistical Inference.

    we may assume that there is no relationship between the RV and the factor of interest Outcome 3 Where it is not clear, there are some differences but also some similarities, then we may need a further statistical test to help us to make a decision on this piece of analysis.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work