• 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

    I found the experiment straightforward and simple to follow. I had previously read up about calorimeters in other textbooks to inform myself of the procedure and having carried it out in my preliminary, I was confident with the use of the equipment.

  2. Combustion of Alcohols Investigation.

    From this graph I can construct a hypothesis. HYPOTHESIS: The further you go down the alcohol series (i.e. starting with methanol, followed by ethanol etc.) the more heat is given off during combustion, with both weight and mass as constant.

  1. Molar Heat of Combustion of Alcohols

    burner and the water before and after the experiment and record the temperature of the water at the beginning and end. We use the temperature of the water and the weight of the burner to work out the molar heat of combustion of the alcohols.

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

    show that a product meets certain health, hygiene and safety standards before it can be approved for public purchase and use. As I have mentioned, one way this is accomplished is through the use of ingredients or formulations that were previously tested on animals.

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

    = 3 x 435 = 1305 1(C - O) = 1 x 336 = 336 1(O - H) = 1 x 464 = 464 2(O = O) = 2 x 497 = 994 2(C = O) = 4 x 803 = 3212 4(O - H)

  2. Alcohol investigation

    energy out=5738kJ ?Hcombustion = 4728 - 5738 = -1010kJ per mole Propanol + oxygen = carbon dioxide + water C3H7OH + 4.5 O2 = 3CO2 + 4H2O H H H O=O O=C=O H-O-H H-C-C-C-O-H + O=O = O=C=O + H-O-H H H H O=O O=C=O H-O-H 0.5(O=O)

  1. Comparing the enthalpy changes of combustion ofdifferent alcohols.

    Amount of oxygen present How will my method give me accurate and reliable results? The plan that I have used will provide accurate results as I am using equipment that has a fairly high degree of accuracy. Another measure of accuracy is how well I can read the equipment that I am using.

  2. GCSE Chemistry Revision Notes - everything!

    This will give you the relative formula mass (Mr). The relative formula mass of water is 18. (2x1)+ 16 = 18 As an alternative to trying to consider masses of individual atoms, it is possible to consider a large number of atoms. The mass of magnesium atoms will always be twice the mass of carbon-12 atoms, provided equal numbers of atoms are compared.

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