• 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

Investigation on the combustion of Alcohols.

Extracts from this document...


Investigation on in to the combustion of Alcohols Hypothesis As the number for carbon atoms in alcohol increases the more energy is released. I am going to conduct an experiment, which will allow me to compare the heat energy given off by three alcohols, those being ethanol, propanol and butanol. These alcohols have a difference of one carbon atom within there atomic structure. I am going to investigate the amount of energy given out per mole once we burn the alcohol, which is the enthalpy of combustion (?H c). This can be supported with the calculations of the bond energies We know that chemical bonds are broken in reagents for this to happen energy must be put in and also chemical bonds are made in the products when this happens and energy is given out. How much energy has to be put into break a given bond or how much is given out when this bond is made depends on the strength of the bond The net energy change ?H depends on the relative strength of the bonds being made and broken. Exothermic reactions Exothermic reactions stored chemical energy is converted into heat energy because the bonds being broken are weaker than the bonds being formed. ...read more.


Safety Precautions In order to ensure safety throughout the experiment I will wear safety goggles and make sure that the hot water is handled carefully therefore ensuring that there is no spills or burns. Obtaining evidence During the experiment, I obtained two sets of results, which will enable to have a wider range of results. During the experiment, I made sure that I wore safety goggles and I handled the hot water with care. The results I took are in the tables below. The temperature indicates the temperature of the beaker of water and the mass indicates the mass of the spirit burner before and after the experiment. Constants that were kept: During the experiment, I kept the length of the wick 1cm and the distance between the wick and the beaker was 10cm. The mass of the water was 100g the length of time was 100 seconds. Ethanol Starting temperature 17 17 End Temperature of Water 39 38 Temperature Change of Water 22 21 Starting mass 180.89 181.56 Ending Mass 178.06 179.09 Mass Change 2.83 2.47 Propanol Starting temperature of Water 20 20 End Temperature of Water 45 43 Temperature Change 25 23 Starting mass 179.60 180.35 Ending Mass 176.50 177.23 Mass Change 3.1 3.12 Butanol Starting ...read more.


Also, the water would have conducted through the beaker and also through convection through the surface of the water. And also, the water would have escaped through radiation. Then heat could have been lost through the flame as in my experiment there was a ten centimetre gap between the wick and the beaker, therefore heat loss could have been lost through that. Therefore, these factors made the experiment unsuitable. I improvements I could have made to the experiment I would have made, is that I would insulate the beaker with foil and cotton wool to reduce the heat loss. Via conduction and radiation. I would place a lid over the beaker to stop evaporation and I would use digital thermometer to record the readings. I would use a pipette to measure the volume of the water this would therefore make it more accurate than a measuring cylinder. And also I would reduce the distance between the sprit burner and beaker to reduce the amount of heat lost. To extend this investigation I would extend the range of alcohols used. I would use the next to after for example pentanol and hectanol and perhaps go as far as octanol. The prediction for that experiment would be the same as this one. As you increase the carbon atoms the more energy that is released. 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 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. Determining the water of crystalisation

    Although I obtained the exact value of number of moles of water presented in hydrated copper sulphate I still got the uncertainty of 1.19%, which could be because of highly, used equipment available at my school. Moreover the purity of salt could not be stated, as the source of that salt was unknown.

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

    After putting the wire loop, with sample substance on it, through the flame, we had to sterilise the wire loop with hydrochloric acid (HCl) so there was none of sample A left over when we scooped up some sample B.

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

    Additional, style customization may be possible to a specific extent. Shoes and lasts can only be produced when an order is placed by an end-consumer. Definition: A two-way intensive relationship for purchasing a product or service to a particular unique specification.

  2. Redox reactions and the halogens.

    as the number of bonded pairs of electrons increases the bond angle increases. Also the less pairs of lone electrons there are the greater the bond angle. Covalent Giant Structures These are 3 dimensional networks of atoms bonded with covalent bonds. Carbon can form giant covalent structures, diamond and graphite.

  1. Combustion of Alcohol's.

    Likewise, Methanol releases the least amount of energy, so it will use more mass to heat the same amount of water. To make sure that my experiment is as fair as possible, I will use the same amount of water; the same temperature rise and I will keep the test tube the same distance from the alcohol.

  2. An experiment to investigate the factors that determine the amount of energy released when ...

    Different isomers may have different properties, even though if they contain the same amount of different atoms. We can again see a relation between the number of carbon atoms in an alcohol and the number of hydrogen atoms. Like alkanes, there is twice as much hydrogen atoms as carbon atoms plus two extra hydrogens.

  1. Ions - a qualitative analysis on our chemicals by flame testing.

    The goggles are made out of thick plastic which prevents any liquids entering the eye and causing any harm. Many people who wear contact lenses are under the illusion that there contact lenses will perform as eye protection not realising that the contact lenses are creating a risk of chemicals

  2. Investigating how much energy is produced when burning alcohols.

    I can come to predict that the longer the molecular structure in the alcohol the more energy it will take to remove the bonds. So when I come to predicting results I can safely say that pentanol will evolve more energy than methanol simply because it has more bonds to break.

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