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

Investigating the combustion of varying alcohols.

Extracts from this document...

Introduction

Investigating the combustion of varying alcohols Aim To find the different rates for the combustion of alcohol. The aim is to find out how much energy is produced when burning these alcohols. Prediction As the alcohol burns, the temperature of the water will increase and the weight of the alcohol will decrease. This is due to evaporation that takes place because of the heat. Alcohols react with oxygen in the air to form water and carbon dioxide. The reaction that is involved in burning alcohols is exothermic because heat is given out. From this reason the reactant energy is higher than that of the product. I predict that the more bonds there are holding the carbon, oxygen and hydrogen atoms together; more energy will be required to break them apart. For example Ethanol has the formula C H OH. In this formula you have five C-H bonds, one C-C bond, one C-O bond and one O-H bond. To separate these types of bonds you require a certain amount of energy. Type of Bond Energy Required (joules) C-H 410 C-O 360 O-H 510 C-C 350 O=O 496 C=O 740 To separate C-H bond you need to apply 410 joules of energy. ...read more.

Middle

* Measure the temperature. * Re-weigh the alcohol and burner. * Calculate the difference. * Record the results. * Repeat these stages 2 times for each different alcohol. This will produce an average result. Results Ethanol Weight Before Weight After (g) Temp before Temp After (�C) 162.43 162.1 21 30 162.1 161.7 18 28 Ave. Weight Difference (g) Ave. Temp Difference (�C) 0.365 9.5 Propanol Weight Before Weight After (g) Temp before Temp After (�C) 189.11 188.7 20 25 188.7 188.3 19 27 Ave. Weight Difference (g) Ave. Temp Difference (�C) 0.405 6.5 Butanol Weight Before (g) Weight After Temp before (�C) Temp After (�C) 222.7 222.2 18.5 28.5 222.2 221.9 19 29 Ave. Weight Difference (g) Ave. Temp Difference (�C) 0.4 10 Pentanol Weight Before (g) Weight After (g) Temp before (�C) Temp After (�C) 215.2 214.8 18 32 214.8 214.45 19 32 Ave. Weight Difference (g) Ave. Temp Difference (�C) 0.375 13.5 Collected Results Alcohol Ave. Weight Difference Ave. Temp Difference Ethanol 0.365 9.5 Propanol 0.405 6.5 Butanol 0.4 10 Pentanol 0.375 13.5 Analysis The energy is given out when forming the bonds between the new water and carbon dioxide molecules. ...read more.

Conclusion

Somewhere in the experiment I must have slipped up because my results differ slightly to what I had hoped would happen. Alcohol Calculation Transfer by 1 gram of fuel Butanol 5670 60 94.5 Ethanol 4200 46 91.30 These two results didn't seem to fit with the others. Ethanol's transfer rate should have been higher than that of the Butanol. Overall I think my experiment was fairly accurate. However, I could have done certain things to make my results more accurate. Improving accuracy * I would have used a more accurate instrument to measure the temperature with, as this would have given me much better and more accurate results. * Also I would have used better equipment to reduce the heat loss in the experiment. Conclusion I have found that my prediction was correct. In my prediction I said that the amount of heat produced per gram would increase as the number of chemical bonds in an alcohol increases. This statement turned out to be true. So, I conclude that the most efficient alcohol out of the ones that I had investigated was Pentanol, and the least efficient was Ethanol. Sian Chesher Chemistry Coursework 5th February ...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. Investigating the Combustion of Alcohols

    + (12�1) + 16 = 88 g Number of moles of pentan-1-ol burned = mass burned mass of 1 mol =0.61g = 0.0069 mol 88 Enthalpy Change of Combustion of = Energy transferred Pentan-1-ol ?HC Number of moles = -7875 J 0.0069 mol = -1136065.574J = -1136065.574J / 1000 =

  2. Comparing the enthalpy changes of combustion of different alcohols.

    the surrounding area, the heat did manage to find other ways out. Therefore most of the heat did not go to the water. A lot of heat was also lost to the equipment. After heating the metal calorimeter I noticed that each time a layer of black soot was forming under the copper can and up the sides of it.

  1. "Could Sainsbury's add value to their business by using an alternative fuel for their ...

    emissions at the point of use and are extremely quiet * Electric vehicles produce no tailpipe carbon dioxide emissions * Electric vehicles are not subject to Vehicle Excise Duty * Lower Personal Benefit in Kind (BIK) tax liability * Enhanced capital allowance rate of 100% in the first year *

  2. Molar Heat of Combustion of Alcohols

    (This is shown in detail a little later. Safety The experiment we are going to carry out is relatively safe but obvious precautions such as not standing whilst doing the experiment will have to be followed. Goggles and gloves will be worn at all times both when conducting and following the test.

  1. Comparing the enthalpy changes of combustion ofdifferent alcohols.

    For example it will be easy to accurately read the reading on the digital balance but it will be harder to accurately read the temperature on a thermometer or the amount of liquid in a measuring cylinder. I am keeping the variables that I do not wish to change as

  2. Which Alcohol is the best fuel?

    8. Take the final temperature on the thermometer after it has stopped rising and record as the 'ending temperature.' 9. Calculate temperature change by subtracting the starting temperature away from the ending one. Also calculate the mass change of alcohol and burner by subtracting the ending mass from the starting one.

  1. The Combustion Of Alcohol

    if I do it vice versa ,use to little water, I risk having to large of a temperature increase , the reading will be much higher, also the water may boil and evaporate therefore changing the volume of water and ruining the whole experiment.

  2. GCSE Chemistry Revision Notes - everything!

    All Group 1 metal ions are colourless. This means that their compounds will be colourless or white unless they are combined with a coloured negative ion. Potassium dichromate (VI) is orange, because the dichromate (VI) ion is orange. The hydroxides all form strongly alkaline solutions.

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