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

The aim of this experiment is to calculate the enthalpy change in various alcohols.

Extracts from this document...

Introduction

CHEMISTRY 3: Energy, rate and extent of reaction AIM The aim of this experiment is to calculate the enthalpy change in various alcohols. HYPOTHESIS Energy is produced when a fuel is burned. The fuel can be used to heat water in a calorie meter. In order to calculate the energy produced by the fuel, the mass, specific heat capacity and temperature of the water need to be known. The enthalpy change can then be calculated using the following formula: ?H=mc?t Where ?H=Enthalpy change, m=mass, c=specific heat capacity, and ?t=change in temperature. Specific heat capacity is the energy needed by one gram of a substance to raise its temperature by 1�K. The specific heat capacity of water is a standard of 4.2J/gk. In this experiment, the fuel to be used is alcohol. ...read more.

Middle

content onto base of stand * Place calorie meter onto clamp and lower so that the base of the calorie meter is approximately 2cm above the spirit lamp. DO NOT adjust this height when repeating the procedure * Measure 50cm� of distilled water * Pour into calorie meter * Put cork lid onto calorie meter, and place thermometer through the central hole in the lid. Take care to make sure that the thermometer is not touching the base of the calorie meter * Wrap a loose layer of aluminum foil around the clamp stand to cover the calorie meter and spirit lamp, leaving a small gap at the base * Record the start temperature of the water * Light spirit lamp and record temperature of water at 30 second intervals for three minutes * After three minutes, extinguish flame on spirit lamp * ...read more.

Conclusion

CALCULATIONS AND OBSERVATIONS Methanol: CH3OH ?H=mc?t ?T=49-22 =27�C ?H=50x4.2x27 ?H=5,670j/g 5670/1000 =5.67 ?H=5.674j/kg Propanol: C3H7OH ?H=mc?t ?T=50-20 =30�C ?H=50x4.2x30 ?H=6,300j/g 6300/1000 =6.3 ?H=6.3j/kg Pentanol: C5H11OH ?H=mc?t ?T=48.5-23 =25.5�C ?H=50x4.2x25.5 ?H=5,355j/g 5355/1000 =5.355 ?H=5.355j/kg Octanol: C8H17OH ?H=mc?t ?T=52-21 =31�C ?H=50x4.2x31 ?H=6,510j/g 6510/1000 =6.51 ?H=6.51j/kg Butanol: C4H9OH ?H=mc?t ?T=45.5-22.5 =23�C ?H=50x4.2x23 ?H=4,830j/g 4830/1000 =4.83 ?H=4.83j/kg Hexanol: C6H13OH ?H=mc?t ?T=47-22.5 =24.5�C ?H=50x4.2x24.5 ?H=5,145j/g 5145/1000 =5.145 ?H=5.145j/kg Ethanol: C2H5OH ?H=mc?t ?T=57-24 =33�C ?H=50x4.2x33 ?H=6,930j/g 6930/1000 =6.93 ?H=6.93j/kg CONCLUSION The principle is that the more carbon atoms that are present in the alcohol molecule, the more energy is given out. As shown in this experiment, Butanol is the worst performer as it was the least energy efficient. Ethanol is the best for combustion, as it is the most energy efficient. To improve this experiment, an increased range of alcohol could be used in order to support this conclusion. ...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. Titration experiment - write up

    Rinse the pipette out with the solution it will contain. 6) Rinse the burette out with the solution it will contain. 7) Check that the burette tap is not too stiff nor too lose, and that it is not leaking.

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

    I have calculated the enthalpy change of combustion (?Hc) using the same method for each of the replicates for each of the fuels. The chart on the next page shows the enthalpy change of combustion for each alcohol and the average enthalpy change of combustion overall.

  1. Investigate the enthalpy change of different alcohol

    (correct to 2 d.p.) Original 1st trial Original 2nd trial Original 3rd trial I have decided to repeat my experiment three times on each of the alcoholic fuel so as to increase the reliability the results. I would then use the average on the increase of water temperature to calculate the energy transferred using the equation mentioned earlier on.

  2. The aim of this investigation is to compare the enthalpy of the following different ...

    This is why the boiling point increases. Bromine water is yellow-orange liquid. There are various groups of hydrocarbons. A family of organic compounds is called a homologous series. The simplest series of hydrocarbons is the alkanes. The general formula of the alkanes is CnH2n+2. They are saturated compounds.

  1. hydrogen peroxide experiment

    If the likelihood that a collision produces a reaction increases then the R of R also increases. Graph Showing How Energy Levels of a Reaction Vary With Time As an increase temperature makes particles move faster the frequency of collisions increases.

  2. Comparing the enthalpy changes of different alcohols

    Mass of fuel burnt (g) Hexane 20 42 22 200 209.15 204.64 4.51 Methanol 20 41 21 200 212.29 203.10 9.19 From these results we can calculate the enthalpy change of combustion for methanol and hexane. Hexane: 1g of water heated through 1�C needs 4.2 Joules of heat 100g of water heated through 1�C needs

  1. Enthalpy Change - Alcohols

    I will then need to get my first alcohol burner and weigh it, once weighed it can be raised up to the calorimeter via the wooden blocks. I will record the weights in a table. The next step would be to carefully place the mercury thermometer inside the calorimeter, and

  2. GCSE Chemistry Revision Notes - everything!

    Magnesium Ribbon burns well, white oxide MgO Slow with water, rapid with steam producing magnesium oxide and hydrogen Aluminium Powder burns well, white oxide Al2O3 No reaction, even with steam ? metal is protected by oxide coating Zinc Power burns, white oxide ZnO Slow in steam, produces zinc oxide and

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