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

Investigating factors affecting the heat of combustion of alcohols.

Extracts from this document...

Introduction

Robert Stewart Investigating factors affecting the heat of combustion of alcohols PLANNING SECTION Introduction Alcohols are organic substances, and consist of Hydrogen, Oxygen and Carbon. All alcohols are toxic but the amount that can be tolerated by the human body varies for different alcohols. For example drinking small amounts of Methanol can lead to blindness and even death. Ethanol is the only alcohol that can be drunk safely and is found in all alcoholic drinks. Throughout this investigation I am going to investigate to different factors that affect the breakdown of an alcohol. e.g. Methane (HCO) + Oxygen (O2) Carbon dioxide (CO2) + Water (H2O) Aim I am going to investigate increasing the chain length and see what effect there is on the heat of combustion. Preliminary Work The point of preliminary work is to find out what things that I should vary and keep constant. For my preliminary work I used computer software called Focus Science Investigation 2. This software enables you to simulate experiments. This means that I am able to quickly carry out experiments to help in planning for my investigation. Alcohol Temperature Increase (oC) Mass of burner before exp. (g) Mass of burner after exp. ...read more.

Middle

I am only changing the quantities however I believe that there will be linear relationship between the number of CH2 sections and the amount of energy released per mole of a certain alcohol. The same bonds will release the same amount of energy, this means that each CH2 section releases the same amount of energy. However it will not be directly proportional as it to go throguh zero on the graph. If it was zero it would mean that no energy was given off from the reaction. OBTAINING EVIDENCE SECTION Changes to Plan There are no parts of the plan that I think that are necessary to change, as I am satisfied with my plan. Results I have put my results into a table, which can be seen overleaf. I have also calculated the enthalpy and added this column into the table. I have put all my results to 3.s.f. I have shown an example of how I worked out the combustion of heat. I am going to take the first result for methanol. Temperature change (oC) = 14 Change in mass of alcohol (g) = 1.10 Specific heat of water = 4.18 Heat evolved (J) = Temperature change (oC) ...read more.

Conclusion

There is little I can do to stop the soot forming, however at the end of each experiment I could wipe off the soot which had formed with a damp cloth to reduce the possibility of this effecting my results adversely. If I were caring this out again, I would just have to make sure that the spirit burners' wick were all the same surface area. Further Work To provide further evidence about the link between concentration and the enthalpy of alcohols I could do the following. I could use different alcohols. Instead of investigating the affect of increasing the length of the chain, I could investigate the position of the O-H section. I could do this by using other alcohols such as Propan-2-ol, Butan-2-ol and Pentan-2-ol comparing them to Propan-1-ol, Butan-1ol and Pentan-1-ol. I could calculate the heat of reaction, and then compare it with data book values. This would allow me to calculate the percentage errors. I could change the constants and variables in such as seeing the effect by varying the distance between the spirit burner and copper can or volume of water. I could even investigate this experiment with another substance and not water and compare the results. I could also look up more information from the Internet. There are websites that have sample data that could be useful towards my investigation. ...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

See related essaysSee related essays

Related AS and A Level Organic Chemistry essays

  1. Peer reviewed

    An investigation into the efficiency of alcohols as fuels.

    5 star(s)

    used different rounding methods and therefore have a difference of 618 between each. All this knowledge allows a precise hypothesis to be formulated. Hypothesis As one goes down the alcohol series, the alcohols will give off more heat, with pentanol being the most heat producing of the alcohols.

  2. Comparing The Enthalpy Change OfCombustion Of Different Alcohols

    The original formula: Energy transferred = (165.18g?4.17Jg-1K-1?65?C) + (68.20g?0.387Jg-1K-1?65?C) = 46487.61J We can see that the temperature change is 65?C. The percentage error for temperature change is 3.077%. I multiply this increase by the original value: 65?C ? 1.03077 = 67?C We can substitute 67?C in place of 65?C in our original formula: Energy transferred = (165.18g?4.17Jg-1K-1?67?C)

  1. F336- aspirin individual Investigation

    of water and ethanol, then neutral iron III chloride is added the concentration of the colour indicate the amount of unreacted salicylic acid present within the sample, therefore the stronger the purple colour the more impure the aspirin is. To test the purity of the sample I must create a

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

    the thermometer at an equal distance of half way up in the center of the can to ensure fairness. Insulation has been another priority of mine to minimise heat loss. I have put 4 heat mat around the sides of the experiment to minimise heat loss by radiation and insulated

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

    * Continue to stir the water and allow the alcohol to burn for five minutes * Extinguish the flame and record the final temperature. * Weigh the spirit burner containing the remaining alcohol on the balance. * Calculate the enthalpy change of combustion using the formula H= mc t (where

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

    2 The mass of aspirin that reacted with NaOH M = n x Mr = 0.0083 x 180 = 1.4850g Therefore the mass of aspirin that didn't react with NaOH. 1.5067 - 1.4850 = 0.0217g Percentage by mass of aspirin (percent purity)

  1. The Relationship Between The Number of Carbon Atoms In An Alcohol And Its Standard ...

    This prediction that I stated is now confirmed through completing the experiment and I am able to use the experiment to support my first prediction. However, the hypothesis is correct only to a certain extent. I stated that the enthalpy of the products would decrease but in fact, they increase.

  2. Comprehensive and Detailed Chemistry notes

    shift the equilibrium in the direction where the change will be counteracted. Using reliable sorces, the lower the temperature, the higher the solubility of Carbon Dioxide. + heat According to Le Chatelier's principle, the heat applied causes the system to absorb some of this applied heat.

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