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

Alcohol Combustion Experiment

Extracts from this document...

Introduction

Adam Franks 10BW GCSE CHEMISTRY COURSEWORK Skill Area:"P". Planning. Background information The breaking of bonds is endothermic, and the making of bonds is exothermic. The difference between the two decides whether a reaction is exothermic or endothermic. We can calculate the theoretical change in energy, by using given values, of the energy required to break certain bonds. Prediction I predict that if the Mr value of the alcohol / and the number of carbon atoms is increased that the heat of combustion will increase. I predict that the heat of combustion will increase in a regular manner aswell. Equations 1C2H5OH + 3O2 2CO2 + 3H2O 1C3H7OH + 4.5O2 3CO2 + 4H2O 1C4H9OH + 6O2 4CO2 + 5H2O 1C5H11OH + 7.5O2 5CO2 + 6H2O 1C6H13OH + 3O2 6CO2 + 7H2O PREDICTING HEATS OF COMBUSTION, BY CALCULATING THEM USING BOND ENERGY VALUES. 1.) Ethanol H H H C C O H + 3O=O 2O=C=O + O H H H H Bonds Broken (ENDOTHERMIC) ?H = + Bonds Formed (EXOTHERMIC) ?H = - 5 x C-H is 5 x 413 = +2065 4 x C-O is 4 x 805 = -2065 1 x C-C is 1 x 347 = +347 6 x H-O is 6 x 464 = -2784 ...read more.

Middle

The alcohol burner was then lit. While the burner was lit the water in the small beaker was stirred. When the temperature of the water had increased to between 15� to 20�, the alcohol burner was blown out. The final temperature of the water was then found, and the final weight of the alcohol was found. To find the heat of combustion the heat change had to be found first. This found by using the equation... Heat change = mass x temperature change x S.H.C Once the heat change had been found the Heat of combustion could be found, and this was done with the equation... Heat of Combustion = -heat change x Mr Mass of alcohol burned In the equations there were two constants. These were, the mass of water (50g), and the specific heat capacity (S.H.C)(4.2). Results: Mass at start Average Mass at Start Mass at End Average Mass at End Temp of water at the beginning Average temp of water at beginning Mass of water Temp of water at the End. Average temp water at End Ethanol 133.700g 133.350g 132.91g 132.63g 18�C 18.5�C 50g 33�C 34�C 132.910g 132.35g 19�C 50g 35�C Propanol 189.797g 189.419g 189.041g 188.617g 20�C 21�C 50g 40�C 41�C 189.041g 188.193g 22�C ...read more.

Conclusion

The clamp, which is metal, and was touching the can will have meant some of the heat, was transferred into the clamp and stand, causing more heat loss form the experiment. In order for this experiment to be more accurate, I would have to insulate the can and the clamps, completely exclude all draughts use a better conductor other than water to heat, and use a thinner can, made of a better heat conducting material. Given that the range of the experiment was only 6 alcohols from methanol to hexanol and that the experiment was only 3 minutes, and the inaccuracies of the experiment, I would say that the evidence is not strong enough to draw firm conclusions from. If this experiment was to be done again, then all the possible sources of error mentioned would have to be counteracted and controlled, as well as using a much wider range of readings of many more alcohols, burn them for different periods of time, heat different substances other that water, investigate the other variables. I would also take many more readings so a much more accurate average could be taken. Other experiments could have been done investigating other organic compounds, such as hydrocarbons, to see if they behave similarly, and investigate them under different conditions, such as at extremes of temperature and pressure. ...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. Marked by a teacher

    Reaction of Alcohol Lab

    5 star(s)

    - Changes to brown colour - On pH paper, it turns to orange (pH value: 3) - Acidic Analysis: Both KMnO4 and Lucas Reagent help to differentiate between tertiary alcohol, secondary alcohol, and primary alcohol. From the results of KMnO4, Butanol A has no reaction, so it has to be the t-butanol.

  2. Titration experiment - write up

    all the solution is transferred using a funnel, from the beaker to the volumetric flask. 8) Add more distilled water to the volumetric flask until it is one cm below the graduation line. At the point continue to add distilled water but with a dropping pipet drop by drop until

  1. The Heat of Combustion of alcohol.

    + 3H2O 1 C-C 346 x 1 = 346 5 C-O 412 x 5 = 2060 1 C-O 358 x 1 = 358 1 O-H 464 x 1 = 464 3 O=O 498 x 3 = 1494 = +4722 Energy Given Out 4 C=O 743 x 4 = 2972 6

  2. Investigate the enthalpy change of different alcohol

    Mr (relative molecular mass) Propan-1-ol �-1,066 60 Butan-1-ol �-1,520 74 Butan-2-ol �-920 74 Cyclohexanol �-2,278 100 Although all of the fuels above belong to the same alcohol homologous series, they all have different enthalpy change due to different molecular structure. Butan-1-ol have an additional CH2 group compare to propan-1-ol, and gives out 454J more

  1. Molar Heat of Combustion of Alcohols

    608718J Test 2 Before After Difference Container Weight 91.71 90.85 0.86 Temp of Water 23 80 57 50*4.2*57=11970 11970/0.86=13919 13919*46 Heat transferred to the copper calorimeter by burning one mole of ethanol. 640274J Test 3 Before After Difference Container Weight 90.85 89.92 0.93 Temp of Water 23 70 47 50*4.2*47=9870

  2. Esters. Esters are formed from an alcohol and carboxylic acid; this is an ...

    For example, in the lethal dosage test, animals are forced to ingest a potentially poisonous substance until half of them die. Common reactions to lethal dosage tests include convulsions, vomiting, paralysis and bleeding. Not only is animal testing inhumane; it is inherently inaccurate.

  1. hydrogen peroxide experiment

    The more particles per cubic centimetre the more collisions take place per second. Particles must collide in order to react. Hence reactions happen quicker if particles collide more often. As reactions happen quicker if particles collide more often and the more particles there are per cubic centimetre the more collisions

  2. GCSE Chemistry Revision Notes - everything!

    Metal Oxide Hydroxide Chloride Nitrate Carbonate Magnesium MgO Mg (OH)2 MgCl2 Mg (NO3)2 MgCO3 Calcium CaO Ca (OH)2 CaCl2 Ca (NO3)2 CaCO3 Magnesium and calcium oxides are strong bases and can be prepared by burning the elements in air or heating the carbonates.

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