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

Investigation in to the existence of hydrogen bonds between ethanol molecules.

Extracts from this document...

Introduction

Experiment 9 Aim A. To investigate the existence of hydrogen bonds between ethanol molecules. B. To measure the strength of hydrogen bond formed between ethanol molecules C. To investigate the formation of hydrogen bonds between molecules of ethyl ethanoate and trichloromethane. D. To measure the strength of hydrogen bond formed between molecules of ethyl ethanoate and trichloromethane. Procedure A. 1. 10 cm3 of ethanol was added into an insulated 50 cm3 beaker by using a measuring cylinder. The temperature of the liquid was measured. 2. 10 cm3 of cyclohexane was added to the ethanol in the beaker. It was then mixed well and the lowest temperature attained was recorded. ...read more.

Middle

The highest temperature attained was recorded. Result Temperature change of solution A B C D Initial(oC) 19.5 20.5 20 18 Final(oC) 16 16.5 27 26 Net(oC) -3.5 -4 7 8 Calculation Liquid Formula Relative Molecular mass Density /kg dm3 Specific heat capacity /kJ kg-1 K-1 Ethanol CH3CH2OH 46 0.81 2.44 Cyclohexane C6H12 84 0.78 1.83 Trichloromethane CHCl3 119.5 1.48 0.98 Ethyl ethanoate CH3CO2CH2CH3 88 0.9 1.92 B. Mass of Ethanol: 0.81?(10?10-6)=0.0000081kg Mass of Cyclohexane: 0.78?(20?10-6)=0.0000156kg Total heat absorbed: 4?(0.0000081?2.44+0.0000156?1.83) =0.000193248 kJ mole of limiting reactant (i.e. ethanol): 0.0000081?1000/46=0.000176086 mole The enthalpy change for one mole of ethanol that the hydrogen bond was broken is: 0.000193248/0.000176086 =1.09746 kJ/mole D. ...read more.

Conclusion

The mixing of the two liquid break the hydrogen bonds. As bonds are broken, energy is needed. Therefore, heat is absorbed and temperature drops. B. * Cyclohexane has to be used in excess in order to ensure that no hydrogen bond is presented. * The hydrogen bond strength obtained was not accurate because there is heat lost to surroundings and to the beaker, which was not considered in calculation. C. * The temperature rises. During mixing, the electropositive hydrogen atom in trichloromethane formed hydrogen bonds with the electronegative oxygen atom in ethyl ethanoate. As bonds are formed, energy is given out. Therefore the temperature rises. D. * It does not matter whether using trichloromethane or ethyl ethanoate in excess because using trichloromethane or ethyl ethanoate in excess does not affect the no. of hydrogen bonds per molecule. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level 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 AS and A Level Organic Chemistry essays

  1. Find the enthalpy change of combustion of a number of alcohol's' so that you ...

    Also the fact that there were no anomalous results proves that my experiment went well. Even though the percentage error was so low, there were still other sources of errors in my experiment/procedure. The main source of error is heat loss.

  2. F336- aspirin individual Investigation

    After I pour the content to all the test tubes into a 100ml conical flask and add 50 ml of water and swirl the mixture. Then I place the conical flask in cold ice for the solution to cool and crystallise.

  1. Enzyme catalysed decomposition of hydrogen peroxide

    constant and time Result: Volume of oxygen produced (Cm3) H2O2 solution (vol) Time (S) 5 10 15 20 25 10 2.0 4.5 7.5 15.5 14.0 20 3.5 8.5 12.0 22.5 20.5 30 4.0 9.5 13.5 27.0 26.0 40 4.0 10.0 13.5 30.5 28.5 50 4.0 10.0 13.5 31.0 29.0 60

  2. Comprehensive and Detailed Chemistry notes

    The equlibrium will shift to the left and more Carbon Dioxide will be released. This means that a lesser amount of Carbon Dioxide will be dissolved. This accounts for the above bold statement. At low temperatures the rate of reaction is very slow.

  1. Oxidation of Ethanol

    that any ethanal produced would not evaporate up through the dropping funnel, instead of being collected. (Ethanol has a boiling point of around while ethanal has a boiling point of . Room temperature on the day was around to )

  2. Comparing the enthalpy changes of combustion of different alcohols

    Firstly, I will ensure that the environment I am working in is clear and suitable for a chemical experiment. This is to minimise the risk of spilling or dropping any of the apparatus I will use. Secondly, I will wear suitable protective clothing whilst doing the experiment, such as safety glasses.

  1. Compare the enthalpy changes of combustion of different alcohols

    I think that if the enthalpy change of combustion applies to alkanes then it will apply to alcohols also. Alcohols have similar properties to their respective alkanes. Alcohols are obtained from alkanes by replacing a hydrogen atom with a hydroxyl group (-OH).

  2. Investigating the Enthalpy Changes of Combustion of Alcohols.

    and therefore calculate the enthalpy of combustion. COMBUSTION OF METHANOL CH3OH + 11/2 O2 CO2 + 2H2O + + In order to combust one mole of methanol, we need 11/2 moles of O2 molecules, and the reaction produces one mole of carbon dioxide and two moles of water.

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