• 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
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13
  14. 14
    14

THE LINK BETWEEN CARBON ATOMS IN A FUEL AND THE ENERGY IT RELEASES.

Extracts from this document...

Introduction

CHEMISTRY COURSEWORK THE LINK BETWEEN CARBON ATOMS IN A FUEL AND THE ENERGY IT RELEASES. PLANNING INTRODUCTION Alcohols generally belong to compounds whose molecules are based on chains of carbon atoms. They usually contain one oxygen atom, which is joined to a carbon atom by a singular bond. This makes them different to other compounds. The oxygen atom is joined to the hydrogen atom as well as the carbon atom, which makes the oxygen a part of a hydroxyl group. These atoms are generally a part of a hydrocarbon chain. These alcohols can take away water from the body, in which a hydrocarbon chain has replaced a hydrogen atom. Alcohols have a general structure of CnH2n+1OH The aim of this investigation is to see the link between the numbers of carbon atom in a fuel with the amount of energy it releases. There would be a change in the amount of energy given off that is getting greater, the more carbon atoms in the fuel, the more there are more bonds to be broken and formed, thus producing more energy. 'In a chemical reaction, bonds in the reactant molecule are broken and new ones are formed. Atoms are rearranged. Energy has to be put in to break bonds, and energy is given out when bonds are formed.' When the total energy put in is greater than the energy put out, the substance cools down (it is endothermic). This is expressed as ? +ve (delta positive). If the total energy put in is less than the energy created, then the substance warms up (it is exothermic). This is expressed as ? -ve (delta negative). I will investigate eight different alcohols using an alcohol or spirit burner, to measure the energy change during burning them by measuring the change in temperature of some water held by a container. This container must have a value of specific heat capacity so I could calculate heat transferred to it as well. ...read more.

Middle

* Repeat this procedure for the alcohols. CHOOSEN ALCOHOLS AND CHEMICAL EQUATIONS * Methanol + Oxygen ==> Carbon dioxide + Water * 2CH3OH + 3O2=> 2CO2 + 4H2O * Ethanol + Oxygen==> Carbon dioxide + Water * 2C2H5OH + 6O2 => 4CO2 + 6H2O * Propan-1-ol + Oxygen ==> Carbon dioxide + Water * 2C3H7OH + 9O2 => 6CO2 + 8H2O * Butan-1-ol + Oxygen ==> Carbon dioxide + Water * 2C4H9OH + 12O2 => 8CO2 + 10H2O * Pentan-1-ol + Oxygen ==> Carbon dioxide + Water * 2C5H11OH + 15O2 => 10CO2 + 12H2O * Hexan-1-ol + Oxygen ==> Carbon dioxide + Water * 2C6H13OH + 18O2 => 12CO2 + 14H2O * Heptan-1-ol + Oxygen ==> Carbon dioxide + Water * 2C7H15OH +21O2 => 14CO2 + 16H2O * Octan-1-ol+ Oxygen ==> Carbon dioxide + Water * 2C8H17OH + 24O2 => 16CO2 + 18H2O THE DIAGRAM OF MY EXPERIMENT Alcohols Mass of the burner and alcohol (g) Mass of the burner after burning (g) Mass of alcohol burnt (g) Mass calorimeter with water (g) Mass of calorimeter alone (g) Mass of water (g) Temperature of water finally (?C) Temperature of water initially (?C) Temperature rise of water (?C) Energy change in Kj/mol - Methanol 1st 167.57 167.25 0.32 152.43 77.21 75.22 30.10 25.90 4.20 145.17 2nd 167.24 166.98 0.26 152.51 77.21 75.30 30.80 25.80 5.00 212.91 3rd 166.98 166.70 0.28 152.14 77.21 74.93 31.30 25.70 5.60 220.44 Average 167.26 166.98 0.28 152.36 77.21 75.15 30.73 25.80 4.93 192.84 Ethanol 1st 156.83 156.61 0.22 153.54 77.21 76.33 30.70 25.90 4.80 351.54 2nd 156.60 156.42 0.18 152.36 77.21 75.15 31.10 25.90 5.20 458.94 3rd 156.42 156.25 0.17 150.67 77.21 73.46 31.40 22.90 5.50 503.41 Average 156.62 156.43 0.19 152.19 77.21 74.98 31.07 25.90 5.17 437.45 Propan-1-ol 1st 174.52 174.39 0.13 152.36 77.21 75.15 30.70 26.00 4.70 739.55 2nd 174.39 174.19 0.20 153.06 77.21 75.85 30.70 26.00 4.70 491.10 3rd 174.19 174.05 0.14 153.20 77.21 75.99 31.30 26.00 5.30 792.46 Average 174.37 174.21 0.16 152.87 77.21 75.66 ...read more.

Conclusion

I have a nice straight graph and no anomalous results, which is brilliant. I think these results came out well because the heat loss actually happened to all the experiments I carried out. In addition, the results are in the least reliable because there was too much heat loss. From my hypothesis, I tried calculating the energy released for each of the alcohols I planned to use and not surprisingly, the results were five times bigger than my initial results. Consequently, I went in search of results in a data book and the results I got for methanol to hexan-1-ol are as follows respectively: 715, 1371, 2010, 2673, 3323 and 3976 joules/mol-. The results also where 3 times larger than the results I got which proves that this method is a very crude way of checking out the energy released in alcohols. Then I went further to calculate the difference in the values I collected from the data book and the average difference were 652.2 while my average was 240. There is nearly three times difference between them. I also took the percentage difference of all of them and the were as follows from methanol to pentan-1-ol respectively: 69%, 68%, 66% 65%, and 64% with a total average of 66.4% this also tells me that nearly 70% of the energy released was actually lost out of the experiment from one means or another which I have listed above. This also shows my results are not reliable at all. Despite all the deficiencies in the results, my result will still says the same thing the results in the data book we says because they are affected by the same things, so they will reduce in the same way. They both proved that the higher the higher the number of atoms the higher the energy released so there surely in a link between the number of atoms and the energy released. ?? ?? ?? ?? ENAJITE JASMINE AGESE 02/05/2007 PAGE 2 ENAJITE JASMNIE AGESE 02/05/2007 PAGE 1 2 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE 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

See related essaysSee related essays

Related GCSE Organic Chemistry essays

  1. Titration experiment - write up

    28.5 28.5 28.5 Initial burette reading 0.00 0.00 0.00 0.00 0.00 0.00 Titre cm3 27.8 28.2 27.4 28.5 28.5 28.5 Average table of results: Titration (cm3) 1 2 3 Final burette reading 28.5 28.5 28.5 Initial burette reading 0.00 0.00 0.00 Titre cm3 28.5 28.5 28.5 In the above table

  2. How Does The Increase In The Length Of The Carbon Chain Affect The Energy ...

    2 * 348 41/2 * O=O 41/2 * 496 ~ 6 * C=O 6 * 743 + 8 * OH 8 * 463 7 * CH 7 * 412 1 * CO 360 1 * OH 463 696 4458 2884 + 3704 360 8162 463 + 2232 6635 Energy difference

  1. Find out which fuel releases the most energy per gram.

    Hypothesis: I predict that hexane will be the fuel that releases the most energy per gram because it has the highest theoretical values for energy per gram since it has the most bonds then any of the other four fuels we are using (methanol, ethanol, propanol, butanol)

  2. Methanol - Bond Energy Calculations

    energies are negative they are all exothermic reactions, and so take energy from their surroundings. j Preliminary - method: Foremost, I will identify the variables as follows:- The fuel to be burned; [fixed variable] Volume/Mass of Fuel; [fixed variable] Amount of water heated; Beaker/Test tube, shape, size etc Distance of

  1. Comparing Energy Given When Different Alcohols Burn.

    cm * Make a three sided cardboard screen to go round the gap between the mini beaker and the calorimeter * Take the temperature of the water * Set the wick alight with a light splint * When the alcohol has completed burning take the temperature of the water *

  2. The Energy Content Of Different Fuels

    Energy produced per mole = energy produced to heat the water No. of moles of fuel used Energy produced per mole = 7350 / 0.047826086 = 153681.82/ 1000 = 153.682 kjmol-1 Average of Ethanol: Average (excluding preliminary) = (171.465 + 133.31 + 153.682)

  1. To Find Out Which Fuel Gives Out the Most Energy.

    Rise in temperature of water (�C) Energy released per gram of fuel (j) 1st 0.85 13 6424 2nd 0.84 12 6000 3rd 0.89 13 5009 4th - - - Average 0.86 12.7 5811 Ethanol Mass of fuel burnt (g) Rise in temperature of water (�C)

  2. Investigating the energy released from burning different alcohols.

    Hence the results of the investigation would be unreliable. The alcohol burner will be used to heat up the 100g, once the temperature of the water has risen by 10oC, according to the calculations made on the previous page that energy given out would have been 4.2kJ therefore. Therefore to work out the heats of combustion (kJ/Mol), the percentage

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