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

The energy released when different alcohols are burned

Extracts from this document...

Introduction

Chemistry coursework The energy released when different alcohols are burned Experimental results for the combustion of alcohols Methanol Ethanol Propanol Butanol Mass of spirit lamp & fuel at start 175.89 188.33 179.67 166.54 Mass of spirit lamp & fuel at end 174.8 187.32 178.71 165.6 Mass of alcohol burned 1.09 1.01 0.96 0.94 Mass of water heated up 100 100 100 100 Temperature of water at the start 25 23 25 24 Temperature of water at the end 50 48 50 49 Temperature rise 25 25 25 25 The experimental results for each alcohol Using our results, we could calculate how much heat was produced in the burning of each alcohol. The reaction is exothermic, as more energy is needed to make bonds The results The alcohol The energy released in the combustion of that alcohol (KJmol ) Methanol 423.85 Ethanol 478.22 Propanal 656.25 Butanol 826.60 The theoretical results for each alcohol In this next stage of the investigation I am going to find the theoretical results, to compare these with the experimental results The alcohol The energy released in the combustion of that alcohol (KJmol ) ...read more.

Middle

As the molar mass for each alcohol increased, less of it was burned. This was because the higher the mass of the alcohol, the faster bonds could be broken, as there were fewer bonds within the substance to break. It took less activation energy to break initial bonds, as the molar mass decreased. If we look at the graph we can also see that there was a considerable difference between the experimental values and he theoretical values. This was because a lot of heat energy supplied by the spirit lamp, was released into the atmosphere, instead of heating up the alcohols. This led to less mass being burned, which was had the effect of decreasing the energy released. The theoretical calculations didn't consideration that heat could be wasted and released into the environment. This agrees with my earlier prediction, and as I can observe, both the set of theoretical and experimental results prove the theory in my prediction to be correct. The results of my calculations show that there is a linear relationship between the molar mass and the energy released. ...read more.

Conclusion

I would have also started the experiment with each alcohol at the same temperature, as more heat causes bonds to have more energy. Using a water bath could have done this. I would have also collected the results of more alcohols, to more strongly support my findings. I would improve my investigation, by not only looking at the exothermic reaction of alcohols burning, but at other exothermic reactions. I would get more substances to test, which would enable me to get an overall picture of how molar mass effects the amount of energy produced. This would prove, without any doubts, the scientific theory I have stated in my prediction and analysis. For example, I could experiment with neutralisation reactions, to see if those exothermic reactions had the same trends. For example, I could react ammonia with sulphuric acid, nitric acid and hydrochloric acid, which all have different molar masses, to find out if the results would be the same, and support the theory put forward in this chemistry Sc1. The resources I used To aid my investigation I used the following resources for reference: * CGP chemistry revision guide * MEG study guide for triple award science * Encarta 99 (exothermic reactions) * Help sheets provided by MR Griffiths Brett Marsden Chemistry ...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 Classifying Materials 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 Classifying Materials essays

  1. Our experiment consisted of two samples of water containing unknown substances, and our objective ...

    Stage 3 - hard and soft water In stage 3, we were given two samples of water, A and B, and we had to find out which sample was 'hard', and which sample was 'soft'. Knowing that hard water used more soap for the same amount of lather than soft

  2. Rate of reaction of different concentrations of sodium thiosulphate.

    This is because there are less water molecules to get in-between the two chemical particles colliding, so there are greater chances for the two chemical particles to collide that may create a reaction (precipitate sulphur) to block the cross. The drop at the first point (8g/dm3)

  1. Rate of reaction of hydrochloric acid on magnesium.

    it easier for particles especially at room temperature to create a successful collision. If the activation energy is high then a small fraction of collisions have enough energy to overcome the activation energy and the success rate of collisions is low, but in this experiment I had no control of the activation energy.

  2. Hydrogen-Oxygen Fuel Cells: Case Study

    Figure 6A: Rubippy Molecule The cost of this catalyst is high, as well as it being inefficient and instable. Research is being conducted to find a more cost-efficient catalyst.(6) The other possibility, an electrolysis solar hydrogen plant, would be ideal as it involves utilizing two renewable resources, water and sunlight.

  1. The role of mass customization and postponement in global logistics

    (Recording companies objected to the scheme). * Federal Express customers track the whereabouts of their parcels in real-time (www.fedex.com). * The Yearlings TV Guide Internet web site creates a personalised TV listing guide based on a personal list of interests (www.yearling.com).

  2. Redox reactions and the halogens.

    This double bond is referred to as a pi bond (?) where the electrons form two electron clouds. (The sigma (?) bond is till present, the single line in the diagram below). The ? is not equivalent to a ? bond as it is much weaker having a lower energy.

  1. Investigation on the combustion of Alcohols.

    Stopwatch Distilled water Clamp Stand Scales Spirit burner Heatproof mat Beaker (250cm2) Ruler Towelling, cloths (for cleaning beakers) Top pan balance (nearest 2 at degrees) Graph paper Method Set up the following experiment as shown in the diagram above. Make sure that the beaker is set exactly 10cm above the wick bearing in mind that the wick is 1cm high.

  2. Combustion of Alcohol's.

    From these results, I can see that Pentanol gives out the most energy when it is burnt, and Methanol releases the least. Using these, I can make a prediction. If Pentanol releases the most energy, then compared to the others, it should take the least amount of mass of alcohol to heat it.

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