• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5
6. 6
6

# Out the bond energies of the alcohols in the homologous series up to Pentanol, comparing them to the data book values.

Extracts from this document...

Introduction

Planning: Aim: To try to work out the bond energies of the alcohols in the homologous series up to Pentanol, comparing them to the data book values. There are a few factors in these experiments that will affect our enthalpies (as opposed to the data book values), which will be outlined later on in the write-up. Equipment: An alcohol burner - This is the heat provider. Heat proof mats - To insulate heat. A stand + clamps - To support the experiment structurally. A thermometer - To discern the starting and finishing temperatures. 50ml of water - Substance to be heated. A copper can - Metal conductor of heat. Electronic scales - To weigh the burners. A measuring cylinder - To measure out the correct volume of water accurately. Hypothesis: I predict that the enthalpies of the alcohols will decrease as the number of carbons increases. The results should reflect the text book values to some extent and show a correlation between each other with a steadily decreasing trend (in terms of the enthalpy). Factors: Here are some of the factors that could have affected our results in some way or other: * There was no proper draught insulation - We only had heat proof mats to insulate the heat and to stop it from heating the surrounding air rather than the can containing the water. * The distance from the heat source and the can itself differed for some experiments as we did these experiments over a period of 3-4 lessons. ...read more.

Middle

5. Make sure the can height is constant for each experiment. 6. Making sure that the lid of the alcohol burner is fixed on top of the burner (to stop the alcohol evaporating away), weigh the burner on a set of electronic scales - making sure the figures are accurate to 2 decimal places. Note down the starting mass of the alcohol burner. 7. Then, place 50ml of water into the copper can that is suspended directly above the alcohol burner. 8. Note down starting temperature. 9. Light the wick of the alcohol burner and quickly set up an insulation barrier of heatproof mats to block out any draughts or unnecessary heat loss. 10. When the temperature of the water has increased by 30�C, hastily blow out the flame that's burning merrily atop the alcohol burner (without spilling the alcohol burner as we managed to do once...) and immediately bung the lid onto the burner and reweigh the alcohol burner on the SAME set of electronic scales to the same degree of accuracy as before. 11. When all has been completed to a reasonable level of satisfaction, breathe a sigh of relief and brace oneself for the repeat of the whole procedure for the same alcohol (do each alcohol twice to validate results) and move up the homologous series steadily using the procedure outlined above to complete the experiment. Equations for the bond energy: Obtaining Evidence: Results: Kj/mol MRs Methanol -726 32 Ethanol -1367 46 Propan-1-ol -2021 60 Propan-2-ol -2006 60 Butanol -2676 Pentanol ...read more.

Conclusion

Also, since we had spread our experiments over several lessons, we hadn't paid much attention to the distance between the can and the alcohol burner so it varied over each lesson. Luckily, we did have some idea of how far away the alcohol burner was from the can so we adjusted it accordingly otherwise there might have been some serious consequences on our results... The lack of Butanol in the lab was a setback for us as we couldn't obtain the results we needed for that alcohol but since we tested each alcohol twice, it didn't really matter (that we didn't get to test Butanol) as we could guess pretty much where Butanol's enthalpy lay on our graph from the results we had obtained during our experiments. The fact that there were no proper draught insulating materials available to us so that we had to make to with using heat proof mats as the draught shields in our experiments was a potential error. Also, there weren't enough to go around so some experiments ended up having virtually no heat insulation and some experiments looking like crude igloos. Possible Improvements: We could all do with a bit more common sense here and there. Possibly our experiment may be executed quicker if we'd another go at it. The distance from the can to the alcohol burner should be logged and kept as similar as possible through the experiments. Some Butanol can be obtained for the next experiment as well because it may have helped... Purchasing some proper draught insulating and heat insulating material wouldn't go amiss either. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Organic Chemistry 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

# Related AS and A Level Organic Chemistry essays

1. ## Preparation of propanone from propan-2-ol

5 star(s)

The suction flask provides a negative pressure and together with the gravitational force, the filtration will be much faster. The crystal and the filter paper can also be air dried quickly. A picture of a suction flask The filter paper is placed on the plate, and the filter paper is moistened with a solvent to prevent initial leakage.

2. ## Find the enthalpy change of combustion of a number of alcohol's' so that you ...

Methanol and Ethanol It is highly flammable and harmful. The vapours will catch fire at temperatures above 13oC. The narcotic effect of ethanol/methanol is well known and may result from inhalation of the vapour. Methanol and ethanol are toxic by inhalation, if swallowed and by skin absorption.

1. ## The aim of this experiment is to investigate the enthalpy change of combustion for ...

* Ideally the alcohols should all be repeated three times and an overall average taken. However time is limiting so I will repeat each alcohol once and compare the accuracy of these results with the results of my previous methods, my bond energy calculations and the values obtained from the data book.

2. ## Comparing The Enthalpy Change OfCombustion Of Different Alcohols

taken from the graph. Methanol 1 46487.61/4.54 32 -328 2 42063.8454/3.82 32 -352 320 Ethanol 1 40737.402/2.76 46 -679 2 50838.8274/3.33 46 -707 320 Propan-1-ol 1 46019.9526/1.88 60 -1469 2 49113.7536/2.84 60 -1038 320 Butan-1-ol 1 46506.4974/2.88 74 -1195 2 52383.5016/3.19 74 -1215 320 Pentanol 1 43719.3717/2.51 88 -1533 2

1. ## The aim of this experiment is to produce Aspirin. This is an estrification in ...

This indicated the end point of the reaction. A note of the new burette reading was then recorded. To work out the volume of the solution added a calculation was made whereby the initial reading was subtracted from this end point value.

2. ## Comprehensive and Detailed Chemistry notes

Plastic pipes, guttering Ethanol Solvent, fuel, drinks Polystyrene Plastic packaging, insulation Chloroethane Solvent, refrigerant HYDRATION: Water adds across the double bond to form ethanol (C2H4 + H20--> C2H5OH) HYDROHALOGENATION: Hydrogen chloride reacts with ethylene to form chloroethane (C2H4 + HCl--> C2H5Cl)

1. ## Modern materials

These tiny tubes are made up of graphene sheets (the atom-thick carbon sheets that stack up to form graphite) that roll up into a tubular structure. If just one sheet of graphene is rolled up, it is called single-walled carbon nanotube.

2. ## Classifications of Alcohols Experiment

The general equation is shown as below: In this test, ethanol, CH3CH2OH react with ethanoic acid, CH3COOH, in the presence of a few drops of concentrated H2SO4 as catalyst and water bath, to form an ester called ethyl ethanoate or ethyl acetate.

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