• 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...


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.


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.


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

    How to ensure greater accuracy of results: 1) Make sure all glassware is clean and dry. 2) Weigh the anhydrous sodium carbonate accurately. 3) Check electronic balance for any dust or spillages. 4) Add exact amount of distilled water for making solution.

  2. Enthalpy Change - Alcohols

    Temp (�c) Alcohol 0 30 60 90 120 150 180 Weight Before (g) Weight after (g) Ethanol 22.4 22.7 23.1 23.3 23.7 23.9 24.2 32.20 30.96 Methanol 20.5 20.9 21.3 21.9 22.1 22.5 23.6 33.28 31.36 Propanol 20.2 20.4 20.7 20.9 21.1 21.5 21.9 30.77 30.28 Butanol 21.2 21.4 21.6

  1. hydrogen peroxide experiment

    hydrogen peroxide break naturally, as hydrogen peroxide decomposes, and reform to create the new products. However they break very slowly as the activation energy for the bonds to break is very high. The catalyst provides a reaction path with lower activation energy.

  2. Comparing the Enthalpy Changes of Combustion of Different Alcohols

    4.2 ? 15 ? (1.18 ? 32) = 170,847 Jmol-1 ?-170.85 kJmol-1 -100 ? 4.2 ? 15 ? (1.07 ? 32) = 188,411 Jmol-1 ?-188.41 kJmol-1 Step 3: Find the average of the 3 ?Hc calculations: {(-201.60) + (-170.85) + (-188.41)} ?

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

    Safety In order to keep my experiment safe I will do the following; * Wear safety goggles and protective clothing (lab coat). * Keep all of the alcohols away from naked flames as they are all extremely flammable. * Work in a safe environment - free from clutter.

  2. Guide To Hendon Central

    However, there is a very good video shop called Apollo on Brent Street if you want a quiet night in with that special someone. We�ve already discussed the possibility of you coming straight out from the army and would like to spend you�re week at the RAF but if you

  1. Comparing the enthalpy changes of different alcohols

    Here are my percentage errors. Hexane Quantity Measured Error Calculation Percentage Error Volume of water using measuring cylinder + - 0.5cm3 0.5 x 100 / 200 0.25% Initial mass of fuel using balance + - 0.005g 0.005 x 100 / 209.15 0.002% Final mass of Fuel using balance + - 0.005g 0.005 x 100 /

  2. GCSE Chemistry Revision Notes - everything!

    The Transition metals They are all typical metallic elements. They are good conductors of heat and electricity, workable, strong and mostly high densities. Apart from mercury, they all have reasonably high to very high melting points. They are much less reactive than Groups 1 and 2, and don?t react as rapidly with air or water.

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