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GCSE: Organic Chemistry

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  1. Investigating enthalpy Change - During this investigation I will be burning a selection of different alcohol's to heat a container of water.

    I will need to ensure that I conduct the experiments safely. As alcohols are very dangerous and highly flammable I will wear my safety goggles at all times. I will need to keep all lose items off clothing tucked in. the lids on the alcohol's must be kept on at all times to prevent evaporation or any spillage's. Apparatus * Retort Stand * Clamp * Copper container * 25ml measuring cylinder * Selection of fuels, methanol, butanol, ethanol and pentanol * Thermometer * Water * Heat proof mat Method * Collect and set up apparatus as shown in the diagram

    • Word count: 1395
  2. To measure and compare the enthalpy change of combustion for four different types of fuels by burning them and measuring the increase in the temperature of water in a calorimeter.

    > Support the calorimeter over a spirit burner containing the fuel you are testing by using a clamp stand. Arrange a suitable position for the draught shields to reduce energy loss to the surroundings. > Weigh the spirit burner (with the lid on) on the top pan balance. > Measure the starting temperature of the water > Replace the burner under the calorimeter and light the wick. > Use the thermometer to stir the water all the time. Heat until temperature had risen by 200C. The thermometer to be used will have a range of 0-110oC. > Extinguish the burner and place the lid on, and keep stirring the water whilst noting down the highest temperature reached.

    • Word count: 1806
  3. Investigation into the Combustion of Alcohols.

    To measure ?H given off, we must use this energy to heat something, this will be water. This however assumes that all the heat produced by combustion of fuel (?H) will equal the amount of heat absorbed by the water (q). So I will measure the amount of energy required to do so. The amount of energy produced by such exothermic reactions can be calculated by using the following formula: Mass of the substance x rise in temp x specific heat capacity. The specific heat capacity is the number of joules required to heat one gram of water by 1�C.

    • Word count: 1983
  4. An Investigation to find out how and Why enthalpy change is affected By the molecular structure of alcohols

    For this investigation, I have chosen the following alcohols, Methanol, Ethanol, Propan-1-ol, Butan-1-ol and 2-Methylpropan-1-ol. I chose this range of alcohols as they allow me to investigate a broader aspect of the affect of the molecular structure on the enthalpy change. I chose Methanol (CH3OH) and Ethanol (C2H50H) as these are both short chain alcohols. This means that these alcohol compounds have a shorter carbon-carbon chain. Methanol Ethanol H H H H-C-O-H H- C - C - O - H H H H I chose Propan-1-ol (C3H7OH) and Butan-1-ol (C4H9OH) as these are examples of longer chain alcohols.

    • Word count: 1477
  5. Investigating the enthalpy change of different alcohols

    Put out the spirit burner. 1. Weigh spirit burner again and record. This is a crude method therefore we did some preliminary testing to find out where improvements can be made and to find out the optimal dimensions e.g. wick height and calorimeter height. These are the amendments we made to get the best results by making the experiment more accurate: * When measuring the amount of water to go in calorimeter I made sure that I measured it at room temperature and the surface of the water on the 200ml line not the sides as this gives a much more accurate measurement.

    • Word count: 1156
  6. An investigation to find out the effect of carbon chains on the boiling point of an alcohol

    The forces between molecules are called intermolecular forces. The stronger the attractions between particles (molecules or ions), the more difficult it will be to separate the particles. When substances melt, the particles are still close to one another but the forces of attraction that held the particles rigidly together in the solid state have been sufficiently overcome to allow the particles to move. When substances boil, the particles are completely separated from one another and the attractions between molecules are completely overcome. The energy required to cause substances to melt and to boil, and thus disrupt the forces of attraction, comes from the environment surrounding the material.

    • Word count: 1485
  7. Comparing the enthalpy changes of combustion of different alcohols

    This will then be used to calculate the amount of mass used during the combustion. 3) Place the spirit burner on the table. Then, using a retort stand with a boss and clamp securely tightened on the stand, attach the copper can with 100 cm^3 water on the clamp and place it approximately 7 cm away from the spirit burner so that the flame can effectively heat the water. 4) Using a 0-110�C thermometer, measure the temperature of the cold water and record this as the initial temperature. This will then be used to calculate the temperature rise.

    • Word count: 1634
  8. Plan and carry out an investigation to determine which of the four alcohols is the most exothermic.

    Breaking bonds need less energy than is needed to form bonds - exothermic reaction. Bigger molecules use high energy to be broken. Methanol and Ethanol have differences as Methanol melts at a higher temperature and boils at a lower temperature than Ethanol. Higher alcohols which include Butanol and Propanol have a higher molecular weight and this is why Butanol is used in perfumes. Ethanol, which is sugar based, with its low freezing point, has a specific use as antifreeze for cars and other vehicles. Methanol + Oxygen > Carbon Dioxide + Water 2CHOH + 3O > 2CO2 + 2H2O Breaking (6x413)

    • Word count: 1319
  9. The physical and chemical processes that are used in an oil refinery

    In the column the hottest temperature will be at the bottom and the coolest at the top. This means that the parts that have boiled from the heating will be gaseous and rise up the column and those that have not will still be in liquid form and will sink to the bottom. As the different gases rise up the column they will condense at different points and as such the liquids they form can be collected. These are called 'fractions'. This process works because the fractions each have their own 'specific boiling point range'. The fractions do not have an exact boiling point temperature, as they are mixtures of lots of hydrocarbons, rather than just one type.

    • Word count: 1434
  10. Combustion of alcohols

    An alcohol is a water molecule with an alkyl group in place of one of the Hydrogen atoms. This is shown here in the example of ethanol: Alcohols are told apart by the number of carbon atoms they have. For example Methanol has 1 carbon atom, Ethanol has 2 carbon atoms, Propanol has 3 carbon atoms and Butanol has 4 carbon atoms. The table continues up to Eiconol, which has 20 carbon atoms but we are only concerned with the first 4 as they are the ones I will be using in the experiment. Alcohols are written with OH on the end as in CH OH (Methanol)

    • Word count: 1055
  11. What energy do fuels liberate when burnt?

    Whenever chemical reactions occur, energy is transferred to or from the surroundings. Energy must always be supplied to break bonds and energy is always released when bonds are formed. During a chemical reaction, old bonds are broken and new bonds are formed. Energy must be supplied to break existing bonds. Therefore, bond breaking is an endothermic process. An endothermic reaction is one, which takes in energy from its surroundings. Usually in the form of heat, which is indicated by a fall in temperature. Endothermic reactions are very rare and hard to spot.

    • Word count: 1636
  12. Investigation to compare the energy given out when alcohol's burn

    = 3338 Energy out 3338 - 2803 = 535 = 535 kJ Ethanol C2 H5 OH + 2O2 ? 2CO2 + 3H2O H H O = O ? ? O = O 496 x 3 743 x 4 + 463 x 6 H - C - C - O - H O = O ? ? H H C - H C - C C - O O - H ( 412 x 5 ) ( 348 ) ( 743 ) ( 463 ) 2060 + 348 + 743 + 463 3231 + 1488 = 4719 5750 - 4719 = 1030 kJ Propanol C3 H7 OH + 4.5O2 ?

    • Word count: 1566
  13. To find out how much energy is produced when burning two hydrocarbons, Ethanol and Paraffin. I will be burning these hydrocarbons to heat up a beaker of water.

    Ethanol has two carbons. The molecular formula is C2H5OH. The structural formula is shown below. Ethanol is not a strictly a hydrocarbon because the molecule contains oxygen as well as hydrogen and carbon. When hydrocarbons are burned in air an exothermic reaction occurs forming carbon dioxide and water. The amount of combustion can vary due to the amount of oxygen present if there is lack of oxygen this is known as incomplete combustion. This is the equation for incomplete and complete Combustion. If there is not enough oxygen present to completely burn the fuel to carbon dioxide and water, other products may form.

    • Word count: 1885
  14. An Investigation into How the Amount of Heat Produced By Burninga Fuel Depends On the Mass of the Fuel Burnt

    805kJ/mol O = O 498kJ/mol Bonds Broken: 1x C - C 1x +347 1x C - O 1x +360 1x O - H 1x +464 5x C - H 5x +431 3x O = O 3x +498 Total = +4730 Bonds Made: 4x C = O 4x -805 6x O - H 6x -464 Total = -6004 ?H = 4730 - 6004 = -1274Kj/mol�� Calculations: H H ? ? H - C - C - OH + 3O = O ==> 2O = C = O + 3O ?

    • Word count: 1337
  15. What is the best Fuel?

    I then took the temperature of the water in the copper can. I put the fuel on a heat proof mat on the table and put the copper can of water in a stand, clamped so that the top of the fuel pot was 130 millimetres away from the bottom of the copper can. I made a shield around the stand, fuel and copper can, using heatproof mats so that the heat didn't travel away from the copper can. I then took the lid off of the fuel pot and lit the wick straight away using a splint.

    • Word count: 1130
  16. Burning alcohols to heat up a can of water

    As alcohol's are very dangerous and highly flammable I will wear my safety goggles at all times. I will need to keep all lose items off clothing tucked in. the lids on the alcohol's must be kept on at all times to prevent evaporation or any spillage's. Apparatus � Clamp � Beaker � Crucible � Measuring cylinder � Weight scales � Aluminium soft drinks can � Thermometer The method that I will use is as follows... � Measure 150cm of water into a can beaker. � Place the can into the grasp of the clamp stand. � Record the starting temperature of the water.

    • Word count: 1585
  17. Comparing fuels

    The other form of bonding is covalent where atoms share electrons to complete their outer orbit. For example Methane, where four hydrogen atoms each share an electron with a carbon atom. Apparatus * Stop clock * Thermometer * Boiling tubes * Measuring cylinder * Spirit burners containing the fuels * Balance * Matches * Clamp stand and boss head * Splints Method * Gather all the apparatus as above * Set all the apparatus as shown below * Fill up a measuring cylinder with 20cm cubed of water and pour it into the test tube * Make sure the test tube is 12 cm off the surface below * Decide what fuel to test and how long should it be tested for.

    • Word count: 1574
  18. Investigate and compare the amount of energy released during the combustion of alcohols with practical and theoretical combustions.

    To calculate the practical results for change in chemical energy I had to first convert the amount of alcohol type burnt into KJ/mol. This was done using the following formula: Amount of energy given off [Energy] ___________________________________ x number of grams per mol Amount Burned (g) I was given the following bond values as below: Bonds Value of Bonds (KJ/Mol) C-H 412 O=O 496 C=O 743 O-H 463 C-O 360 C-C 348 Results Ethanol C2H5OH + 3O2 2CO2 + 3H2O H H O=O O H-O-H | | || H - C - C - O - H O=O C=O H-O-H | | O H H O=O || H-O-H C=O Theoretical H-C x5 = (412x5)

    • Word count: 1126
  19. Find out the difference in energy that is given out by the alcohols Methanol, Ethanol, Propanol and Butanol when they are burned under a tin of water for 3 minutes.

    boils and if you have more it doesn't get hot enough to record a difference between the alcohols in the 3 minutes. In order to make my results more accurate I will put the metal can of water as close to the flame as possible to make sure as little heat as possible is lost into the surrounding atmosphere. I will weigh the spirit burner before and after the experiment so I can see how much alcohol has been lost.

    • Word count: 1566
  20. To Show How the Volume of Fuel Affects the Energy Output In the Form of Heat

    The equation for this experiment is as follows:- CH3CH2OH + 3O2 ??Combustion??? 3H2O + 2CO2 Ethanol + Oxygen Water + Carbon Dioxide Apparatus 1x Stand 1x Boss 1x Clamp 1x Tin Can 1x Heatproof Mat 1x Crucible 31.5mls Fuel(Ethanol)divided into:- 3x 0.5mls 3x 1mls 3x 2mls 3x 3mls 3x 4mls 15x 100mls Tap Water 1x Thermometer Apparatus Diagram Method I plan to use the "volume/mass of fuel" variable to prove whether the volume/mass of fuel affects the energy output. I chose this variable because it seemed to be a useful thing to learn and know about.

    • Word count: 1286
  21. To Find Out Which of the Five Alcohol’s Makes the Best Fuel To Heat Water.

    We will put this under the clamp stand, which is holding the boiling tube of water and a thermometer. We will then time 2 minutes and find out how much the temperature has risen. We will repeat the experiment four times to calculate an average. To make it a fair test we will keep the water volume at 40cm3, the same distance from the flame to the water and fresh water at the start of each experiment. Results: Temperature in �C Tests Before After Change 1 24 30 6 2 22 28 6 3 21 27 6 4 23 28 5 Conclusion: In 2 minutes the ethanol increased its temperature by 1?c from 5?c to 6?c.

    • Word count: 1874
  22. To See If the Size of the Molecule Affects the Heat of Combustion

    Plan: The apparatus I will be requiring for experiment are as follows: * One calorimeter * A clamp stand and clamp * Alcohols in spirit lamps: ethanol - C2H5OH propanol - C3H7OH butanol - C4H9OH pentanol - C5H11OH hexanol - C6H13OH * Matches * Water * Measuring cylinder * Thermometer * Safety glasses * Electronic balance This is the method I will be using: 1. Measure 100cm3 of water and pour into a colorimeter 2. Place the colorimeter in the grasp of the clamp stand 3.

    • Word count: 1082
  23. GCSE Chemistry Coursework-Burning Fuels Investigation

    Afterwards, measure the fuels mass on the scales again and record the waters temperature after the experiment. Record all the results in three different tables divided by the number of runs for each experiment. Once all the fuels have been tested three times find the average of results and record them on a different table. Work out the average temperature rise by subtracting the temperature after experiment by the temperature before and then average it out using all 3 runs. And also work out the energy released by finding the average mass of burnt fuel and then use this formula and record it on a table: Energy released = mass of water x 4.2 x average temperature rise Mass of burnt fuel DIAGRAM: RISK ASSESSMENT: Alcohols and hydrocarbons are flammable and vaporise quickly and easily.

    • Word count: 1452
  24. To investigate the heat outputs of fuels

    Initial mass of crucible (g) Final mass of crucible (g) Initial temp (oC) Final temp (oC) Rise in temp (oC) Methanol Ethanol Propanol Methanol Mass of [Methanol, Ethanol, Propanol] burned (g) Moles of [Methanol, Ethanol, Propanol] burned (g) Rise in temp (oC) Heat given out in reaction (kJ) Heat given out per mole (kJ) Ethanol Mass of [Methanol, Ethanol, Propanol] burned (g) Moles of [Methanol, Ethanol, Propanol] burned (g) Rise in temp (oC) Heat given out in reaction (kJ) Heat given out per mole (kJ) Propanol Mass of [Methanol, Ethanol, Propanol] burned (g) Moles of [Methanol, Ethanol, Propanol] burned (g)

    • Word count: 1073
  25. To measure the energy released by 1g of fuel from a series of alcohols which represent hydrocarbons.

    Take care when handing the fuels and wash your hands if the fuel is spilt yourself. Results: Run 1 Run 2 Run 3 Fuel Mass of fuel before (g) Mass of fuel after (g) Temp to start Temp after Mass of fuel before (g) Mass of fuel after (g) Temp to start Temp after Mass of fuel before (g) Mass of fuel after (g) Temp to start Temp after Methanol - - - - - - - - - - - - Ethanol 191.70 187.97 25 45 207.26 206.58 23 37.5 191.31 190.38 22.3 41.1 Propanol 216.25 213.76 28 73 239 235.8 22 60 224.17 220.76 22.3 35.2 Butanol 215.09 212.77 26 49.5 231.13 227.84 24

    • Word count: 1870

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