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

Determining the effect of carbon chain length of an alcohol on its fuel efficiency

Extracts from this document...

Introduction

Determining the effect of carbon chain length of an alcohol on its fuel efficiency * Aim: The aim of this experiment is to determine the enthalpy change of methanol, ethanol and propanol. Also to investigate how and why the molecular arrangement of the alcohol affects the enthalpy change. * Variables: * Independent Variable: Type of Alcohol * Dependent Variable: Change in Temperature * Controlled Variable: Mass of the calorimeter, Mass of water, Mass of the spirit burner * List of Apparatus: * Clamp * Beaker (2*100cm3) * Calorimeter (Copper) * Methanol (200g) * Ethanol (200g) * Propanol (200g) * Weighing Balance (�0.01g) * Thermometer or Probe (-100C to 1100C, �0.20C) * Spirit burner * Heating mat * Tripod * Pipe-clay Triangle * Safety Glasses * Aluminum Foil * Measuring Ruler (�0.05cm) * Procedure: * Set up the stand and the clamp at a set height above the wick of the spirit burner. * Weigh 20.00 grams of water on a pre-weighed beaker using a 2 d.p weighing balance. * Put the 20.00 grams of water in the calorimeter and record its temperature using a probe of thermometer. ...read more.

Middle

= (12.01) + (4*1.01) + 16.00 = 32.05g mol-1 Amount of Ethanol Burned = 0.30g/32.05g mol-1 = 0.009 moles Heat Energy required to raise the temperature of 20g of water by 34.7oC = (20 *4.18 *34.7) = 2900.92J It can then be implied that the heat energy evolved from 0.009moles of ethanol = 2900.92J Heat Energy evolved by one mole of ethanol = 2900.92/0.009 = 322257.778J = -322kJ Uncertainty of the mass of the water = (0.01/20)*100 = 0.05% Uncertainty of the Temperature = (0.2/34.7)*100 = 0.58% Uncertainty of the mass of the ethanol = (0.01/0.30)*100 = 3.33% Total percentage uncertainties = (0.05+0.58+3.33)= 3.96% * 3.96% of 322kJ = 12.7 kJ mol-1 Thus CH3OH(l) + O2(g) CO2(g) + 2H2O(l) ?H = -322.2 � 12.7 kJ mol-1 Calculation for Ethanol: Initial Mass of the Spirit Burner = 210.76g � 0.01g Final Mass of the Spirit Burner = 210.36g � 0.01g Mass of ethanol burned = 0.40g � 0.02g Molar Mass of Ethanol (C2H5OH) = (2*12.01) + (6*1.01) + 16.00 = 46.1g mol-1 Amount of Ethanol Burned = 0.40g/46.1g mol-1 = 0.00868 moles Heat Energy required to raise the temperature of 20g of water by 37.5oC = (20 *4.18 *37.5) ...read more.

Conclusion

These values are relatively close to each other and support my hypothesis which was that as the carbon chain length increased the enthalpy of combustion would increase. I encountered several sources of errors during this lab such as heat energy from the flames of the spirit burner which did not fully heat up the water due to the draught of air caused by the air conditioner. This source of error could be overcome by blocking this source of air off or carrying out this experiment at a different location. Another source of error encountered was heat loss from the beaker in which the water was boiled and this was because the beaker is not a perfect heat insulator. To combat this error, aluminum foil could have been used to wrap around the beaker and the experiment, thus reducing the amount of heat lost and ensuring most of the heat from the spirit lamp went to heating up the water. A major source of error in my lab also was the incomplete combustion of the alcohols due to a limited supply of oxygen thus the incomplete combustion of the alcohol formed carbon as soot and carbon monoxide. Preventing incomplete combustion would be to perform this experiment in an even more oxygen richer environment such that the alcohol could burn completely to form carbon dioxide and water. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate 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 International Baccalaureate Chemistry essays

  1. The purpose of this experiment was to determine the molar mass of carbon dioxide ...

    Mass of flask with air - mass of air = mass of flask. 48.303 g - 0.129613 g = 48.173387 g 4) Calculating the mass of carbon dioxide in the flask. After calculating the mass of the flask, the mass of CO2 was found by subtracting the mass of the flask from the mass of the flask with carbon dioxide.

  2. Enthalpy of Combustion of Alcohols Lab

    (4.186 Jg-1k-1) (11.5 k) Q = 4813.9 J Q = 4.81 kJ Step 3: Calculating the enthalpy of combustion ?HC = Q/mol ?HC = 4.81kJ 0.0480mol = 100 kJ/mol However it is exothermic, that is why it has to be negative = - 100 kJ/mol Step 4: Calculating the uncertainties Uncertainty for mass of alcohol combusted = (0.02g/1.53g)

  1. Aim To investigate the chemical properties of alcohol

    Thus the equilibrium above is further to the left in the case of ethanol than water. Hence, ethanol is the weaker acid. When glacial ethanoic acid, concentrated sulphuric acid and ethanol are mixed, an esterification reaction occurs the product of which is ethyl ethanoate.

  2. Molar Heat combustion chemistry - investigate the effect of molar mass on the molar ...

    Re-weigh the burner and record its final mass. 11. Repeat your measurements 2 more times for each alcohol. 12. Perform the experiment using ethanol, methanol, 1-propanol, 1-butanol and 1-pentanol. Raw Data: Table 1. Quantitative Raw Data Alcohol Trial Initial water temperature (?C � 0.5?C)

  1. Lab 1 - Determining Hydrate Formulas

    out that I forgot to minus the mass of the crucible with the lid from the mass of the Zinc (II) Sulfate (ZnSO4) salt in the crucible with the lid. Only by doing this will I get the true mass of the hydrated Zinc (II)

  2. The aim of this experiment is to examine the enthalpy of combustion of the ...

    Apparatus 1. Two clamps and a stand 2. Beaker 3. Measuring cylinder ( 50cm ³ ) 4. Balance ( 0.01 g ) 5. Thermometer 6. Alcohols : methanol,ethanol,propanol,butanol,pentanol 7. Boiling tube 8. Five alcohol burners 9. Matches Method 1. Clamp a boiling tube on a stand,then clamp a thermometer 2 cm above the bottom of the boiling tube.

  1. Measuring the fatty acid percentage of the reused sunflower oil after numerous times of ...

    MATERIALS: ⺠0.01 M, 1000.0 ± 1,0 ml KOH (which is prepared with ethyl alcohol) 4 Taken and modified from < http://www.culinaryâyours.com/frying_oil> 9 ASLAN Özge Cemre D129077 ⺠Phenolphthalein (which is made a 0.5% solution with 95% ethyl alcohol) ⺠Ethyl alcohol (100.0 ± 1.0 ml for each trial)

  2. The chemistry of atmospheric and water pollution.

    Filtration The water from the settling tanks is pumped into filtration tanks which contain layers of sand and gravel. The water passes through the fine sand + gravel filter bed; this removes any remaining particulate matter in the water that did not settle in the tank in the previous step.

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