• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12
  13. 13
  14. 14

Burning fuels.

Extracts from this document...


Our aim is to find out which fuel out of the following 4 1. METHANOL - CH3OH 2. ETHANOL - C2H5OH 3. PROPANOL - C3H7OH 4. BUTANOL - C4H9OH Gives the most energy when it is burnt. 2. To find out if there is a correlation between energy and a certain number of carbons. Burning fuels is a combustion (oxidation) reaction: for example 2C H3OH + 302 2CO2 + 2H20 + ENERGY Reaction A chemical reaction takes place in two steps. STEP 1 The chemical bonds in the reactants are broken to release the atoms, which make the reactants. For this to happen we need to provide energy. One of the reactions that we must give it is called ENDOTHERMIC (Heat energy put in). H O H O H O H 2(H -C - O - H) + 3 (O=O) O H C H O H O H O H O H C The bonds that are broken are: C - H x 6= 413 x 6= 2478 C - O x 2= 335 x 2= 670 O - H x 2= 464 x 2= 928 O = O x 3= 498 x 3= 1494 5570 EACH CHEMICAL BOND HAS ITS OWN VALUE BOND ENERGY KJ/MOL H - H 436 C - H 413 C - C 347 C - O 335 O = O 498 O - H 464 C = O 740 STEP 2 O H O H O H O H C 2 C=O + 4 (H - O - H) ...read more.


fuel * Always 50cm3 of water * Same thickness of metal * Same colorimeter * Always 1gm of fuel * Start with coldwater each time Obtaining results Table Of Results Prediction For my prediction I have used lots of background knowledge and done some preliminary experiments. As you can see I have worked out the theoretical energy release for each alcohol and from these I would predict that as the number of carbon atoms go up so will the heat of combustion. I believe that the results will be proportional to the amount of carbon atoms. I believe this because every time you add an extra carbon bond you also add two more hydrogen bonds, which means that the relative molecular mass will increase as well. I also predict that this will be a constant amount. When I achieve my results I will need to figure out the actual amount of energy given out and the molecular mass plays a big part in this. Analysing I think my results tables and graphs clearly show the pattern that I have found in this experiment. That is that heat combustion does increase when the amount of carbon atoms increases. A table that answers the question more specifically and clearly is shown below: How many grams in one mole of each fuel? Fuel No. Of carbons Mass of 1 mole (g) ...read more.


As we proceeded with the experiment we came across two types of reactions: ENDOTHERMIC: A reaction that we must give it energy. This is when bonds break, and heat energy is put in. EXOTHERMIC: When new bonds are made energy is given out. We can prove this by using scientific knowledge because our scientific knowledge tells us that a chemical reaction takes place in two steps. The chemical bonds in the reactants are broken to release the atoms, which make the reactants. But for this to happen we need to provide energy. And the energies are as I said ENDOTHERMIC and EXOTHERMIC. We also found out that the prediction agrees with the conclusion because we predicted that the more carbon atoms a compound has the more energy it will release. Later on we investigated the experiment further and found out that Energy Joules/gm = 4.2 x 50 x temperature increase 4.2 is needed to increase the temperature of 1gm of water by 1C. Using this we found out that Butanol released 3255 Joules/gm. After this I can conclude that my initial prediction was actually right but I didn't allow for all of the experimental errors. I conclude that carbon atoms in alcohols do have an effect on the heat of combustion. As the amount of carbon atoms go up the heat of combustion does. This is because every time you add another carbon atom you are also adding 15 onto the relative atomic mass that plays a big part in calculating the end results. NAME:SUBHAN ALI 11-12-2003 SCIENCE COURSEWORK DR HOLMES ...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

    Balances may also read to 2 decimal places i.e. they have readings every 0.01 g. This means a reading of 1.00 g is more than 0.995 g but less than 1.005 g. The percentage error in a reading of 1.00 g is 0.005/1.00 x 100 = 0.5%.4 Method Preparation of

  2. Burning Fuels - Fuels are substances that release energy when they react with oxygen. ...

    Photochemical Smog In the presence of sunlight oxides of nitrogen and unburned hydrocarbons react with water vapour and oxygen in the air to form complex mixtures of chemicals including ozone (O3) which can be very irritating to our eyes and lungs.


    METHANOL CH3OH ETHANOL CH3CH2OH PROPAN-1-OL CH3CH2CH2OH BUTAN-1-OL CH3CH2CH2CH2OH PENTAN-1-OL CH3CH2CH2CH2CH2OH ANALISING AND CONSIDERING EVIDENCE CALCULATIONS HEAT EVOLVED IN EACH ALCOHOL The formula to find the heat evolved is: (Rise in temperature ? mass of water ? 4.2) + (Rise in temperature ? mass of calorimeter ? specific heat of calorimeter)

  2. Energy Transfer in Fuels

    I need to keep certain things constant or I may need to change certain things so that it will be a fair test, and each fuel has the equivalent experiment. Here is a list of how I can make it a fair test: - Water - This will need to be constant at 100g.

  1. Investigating the energy released from burning different alcohols.

    all of the bonds in the ethanol and oxygen molecules, more energy id given out. As the energy given out from the formation of these new bonds is greater than the activation energy taken in to start the reaction, the reaction gives out more energy than it takes in; hence it is an exothermic reaction.

  2. The Energy Content Of Different Fuels

    Therefore, the prediction is = -4984 / 2 = -2497 kjmol-1 This is therefore a table of all my calculations together: Fuel Expected Enthalpy of Combustion Methanol -529 kjmol-1 Ethanol -1021 kjmol-1 Propanol -1513 kjmol-1 Butanol -2005 kjmol-1 Pentanol -2447 kjmol-1 With these results there is a special pattern.

  1. Hydrocarbons As Fuels.

    The price of any fuel includes many factors: - the costs of finding it - extraction, refining and transportation - all the company overheads, such as buildings, salaries and advertising - fuel taxes levied by governments - and the capital costs of the equipment needed to burn it - A

  2. GCSE Chemistry Revision Notes - everything!

    An impurity lowers the melting point and raises the boiling point. Solids have definite shape and volume. Liquids have definite volume but no definite shape. Gases have neither definite shape nor volume. Solids tend to have high densities; liquids have lower whilst gases always have low densities.

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