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

My investigation is based around the subject of alcohols. The majority of people most commonly know alcohol as being a drink, which is consumed by many socially and is thought to be relaxing, but it actually acts a depressant.

Extracts from this document...

Introduction

Introduction My investigation is based around the subject of alcohols. The majority of people most commonly know alcohol as being a drink, which is consumed by many socially and is thought to be relaxing, but it actually acts a depressant. However in this investigation I am most interested in the chemistry side of alcohols. Alcohols in chemistry form a homologous series of compounds, which means they all have a general formula. They are generally referred to as being the -OH group, which is the functional group of an alcohol. This means that each alcohol contains an -OH bond. The -OH bond shown in the structural formulae determines the types of reactions created by that particular compound. The table below shows the first six alcohols in the series: NAME MOLECULAR FORMULA STRUCTURAL FORMULA Methanol CH3OH H H -C-O-H H Ethanol C2H5OH H H H-C-C-O-H H H Propanol C3H7OH H H H H-C-C-C-O-H H H H Butanol C4H9OH H H H H H-C-C-C-C-O-H H H H H Pentanol C5H11OH H H H H H H-C-C-C-C-C-O-H H H H H H Hexanol C6H13OH H H H H H H H-C-C-C-C-C-C-O-H H H H H H H The members in the series are similar in both physical properties and chemical reactions. ...read more.

Middle

Energy needed to break bonds Energy released when new bonds are formed Reactants Heat Change (KJ/mole) Products This energy level diagram shows an example of an exothermic reaction, where the energy released is higher than the energy needed to break the initial bonds. The heat of combustion is therefore shown by the heat change the reactants required to form the products (in Kilojoules per mole). In this instance, the products would become more stable because energy has been lost. Burning Alcohols Here is an equation to show what happens when an alcohol is burnt in the presence of oxygen: e.g. Ethanol C2H5OH (l) + O2 (g) 2CO2 (g) + 3H2O (l) This equation shows us that carbon dioxide (CO2) and water (H2O) are formed when the ethanol is burnt, and this is true for all alcohols. The products will always be CO2 and H2O but obviously varying in the amounts produced. This process is called complete combustion because all of the carbon (C) is converted into CO2 and all of the hydrogen (H) ...read more.

Conclusion

for the heat of combustion of ethanol: C2H5OH + 2O2 2CO2 + 3H2O ETHANOL OXYGEN CARBON WATER DIOXIDE This equation is balanced, so I will now work out the total bond energy values for each compound, using their structural formulas. Here are the reactant's totals: ETHANOL H H H - C - C - O - H H H 5 C - H = 5 x 413 = 2065 KJ 1 C - C = 1 x 347 = 347 KJ 1 C - O = 1 x 336 = 336 KJ 1 O - H = 1 x 464 = 464 KJ 3212 KJ/mole OXYGEN O = O O = O 2 O = O = 2 x 498 = 996 KJ 996 KJ/mole TOTAL OF REACTANTS = 3212 + 996 4208 KJ/mole The following calculations are for the products from the equation: CARBON DIOXIDE O = C = O O = C = O 4 C = O bonds = 4 x 805 = 3220KJ 3220KJ/mole WATER O H H 2 O - H bonds = 2 x 464 = 928KJ 928KJ/mole TOTAL OF PRODUCTS = 3220 + 928 4148KJ/mole ...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. Investigating the Combustion of Alcohols

    which suggests that there may have been a few limitations to the method used. There were a few limitations in the method. One important limitation was the positioning of the heat proof mats to shield the wick when alight. When an alcohol had to be replaced by another alcohol, the

  2. Molar Heat of Combustion of Alcohols

    In a perfect world I would have liked to redo the test using insulation, a skirt and a more accurate electronic thermometer but we unfortunately did not have time to do this. Heat Absorption in the Copper Calorimeter In our results we did not take into account the energy used to heat the container.

  1. Combustion of Alcohols Investigation.

    APPARATUS: Alcohol burner - to contain the alcohol and to expose it at a steady rate to the air via a wick. Clamp and clamp stand - to hold the beaker of water in place, suspended above the alcohol burner.

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

    1.45g 1.43g 1.44g Starting temperature of water (�C) 22�C 23�C 24�C Final temperature of water (�C) 37�C 38�C 39�C Methanol Replicate four Weight of spirit burner before (g) 236.98g Weight of spirit burner after (g) 235.23g Change in mass of spirit burner (g) 1.75g Starting temperature of water (�C)

  1. The Combustion of Alcohols and the factors affecting these reactions

    5 � C-H: 5 � 412 = 2060 1 � C-C: 1 � 347 = 347 1 � C-O: 1 � 358 = 358 1 � O-H: 1 � 464 = 464 3 � O=O: 3 � 498 = 1494 Total: + 4723 kJ/mole Bonds Making (-)

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

    At present, cosmetics testing is generally faring well without the use of animal testing in areas where it is banned and this trend might continue to take hold of other countries. The practice is particularly controversial because animals may experience discomfort, suffering and ultimately die, all in the name of aesthetics and 'looking good.'

  1. Comparing the enthalpy changes of combustion ofdifferent alcohols.

    * Do not eat or drink during the experiment. * If any substance is dropped on the floor contact the lab technician immediately. * After the experiment is completed wash your hands thoroughly. * Keep a window open to allow ventilation of the room as some of the fuels emit harmful toxins which can cause damage to your lungs.

  2. GCSE Chemistry Revision Notes - everything!

    In the usual case of going straight from solid to gas and vice versa, the process is called sublimation. Particles in a solid are closely packed and vibrate around a fixed point. When we warm a solid, the particles gain kinetic energy.

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