Petrol - In its crude state, petroleum is a virtually useless material.
Petrol In its crude state, petroleum is a virtually useless material. However when refined, the hydrocarbons it contains supply almost half the world's current energy needs and are the starting chemicals from which about 90% of the worlds organic chemicals are made. Fractional distillation is the process by which the different fractions in crude petroleum are separated according to their boiling points. One of the fractions obtained is naphtha. Further fractionation of naphtha yields petrol (C - C alkanes). In the internal combustion engine, a piston compresses a mixture of air and petrol vapour. At the point of maximum compression, an electrical spark ignites the petrol/air mixture and rapid combustion occurs. A typical reaction would be the combustion of octane: The hot gaseous products expand against the piston and force it downwards. This mechanical energy is transmitted to the drive wheels of the car, enabling it to move. Petrol also contains various additives such as lubricants, rust inhibitors and anti-knock agent. Some hydrocarbons have a tendency to ignite spontaneously before maximum compression is achieved. This premature explosion, known as knocking, still forces the piston downwards and powers the vehicle. However, the chemical energy in the petrol is less efficiently converted into mechanical energy. As a result, the vehicle will do fewer miles per gallon.
Planning - Variable input - Alcohol
SKILL P~PLANNING Input Variables Alcohol This is the variable I am going to investigate. An increase in the length of carbon-carbon chains will result in an increase of energy given out. This is due to the longer hydrocarbons having, a greater attraction to each other. Therefore more energy is needed to break them down so more energy is given out since the reaction is exothermic. Volume of Alcohol A greater volume means more molecules of the alcohol. More molecules will mean more atoms, hence more carbon-carbon chains. As is described above more carbon-carbon chains in this experiment will mean more energy. Therefore to keep this variable constant each alcohol will have the same number of molecules. Isomers of Alcohol Isomers may have different structures., and they may have different properties. We know that branched chains have lower boiling points then straight ones. Therefore to make sure that isomers do not effect the experiment only one isomer from each alcohol will be tested. Volume of Water To keep this variable constant the same volume of water for each experiment will be used. Mass of Ceramic Wool To keep this variable constant the same mass of ceramic wool will be used. Container To keep this variable constant only one container will be used for the whole experiment Height of Container To keep this variable constant the container will remain at the
Physics - Delphi Automotives Needle Lift.
AS Physics Coursework Unit 3: Delphi Automotives Needle Lift: A Fuel injector is electronically controlled valve, which contains amongst other things a tightly coiled spring and a needle (see diagram: however this is a electromagnetic fuel injection system). A pump connected to the fuel injector pushes highly pressurised fuel down to the bottom of the injector, causing pressure to build up. When the pressure reaches around 1600 bar (1,600,000,000 Nm-2), the needle is forced upwards, creating a hole in the injector. The fuel then, moves from an area of high pressure to an area of low pressure, dispersing. The tiny nozzle is designed to atomise the fuel, which aids combustion (due to greater surface area). This process is completed a vast number of times per second. Diagram: For many years the Hall effect was not applied practically due to the generated voltage in the metal was so extremely low. However towards the second half of the twentieth century the mass production of semiconductors came underway. Chips based on the Hall effect inexpensive and so were able to be used in a wide range of instances The Hall effect Integrated Circuit is a very small chip that is made up of many transistors. It consists of a thin layer of silicon as a Hall generator (which works to a greater efficiency than gold) and several transistor circuits: to amplify the Hall voltage to the
Which fuel has the most energy?
Science GCSE Coursework Which fuel has the most energy? Aim: The aim of this exercise is to find out, which fuel has the most energy. The fuels that I will be testing are Methanol, Ethanol, Propanol, Butanol and Pentanol. All of these fuels are alcohols. Prediction: I think that Pentanol will be the fuel that will have the most energy. I have made this prediction because I worked out the energy needed in each bond and then how much energy is needed in the balanced equations I drew up for each fuel. Here are the bond energies: C-H 413KJ/mol C-C 347KJ/mol C-O 335KJ/mol O-H 464KJ/mol O-O 498KJ/mol C-O 805KJ/mol Here are the balanced equations: Methanol: CH3O-H + O2 ----- Co2 + H2o Ethanol: C2H5O-H + O2 ----- Co2 + H2o Propanol: C3H7O-H + O2 ----- Co2 + H2o Butanol: C4H9O-H + O2 ----- Co2 + H2o Pentanol: C5H11O-H + O2 ----- Co2 + H2o Once I had the bond energies I could work out how much energy there was in each fuels structure. H Methanol: H - C - O - H = CH3 O - H H C-H: 3 413 = 1239 C-O: 1 335 = 335 O-H: 1 464 = 464 Total = 1239 + 335 + 464 = 2038KJ/mol H H Ethanol: H - C - C - O - H = C2H5O-H H H C-H: 9 413 = 3717 C-C: 3 347 = 1041 C-O: 1 335 = 335 O-H: 1 464 = 464 Total = 2065 + 347 + 335 + 464 = 3211KJ/mol H H H Propanol: H - C - C - C - O - H =
Alkanes and Alkenes
Unit 3 Notes Petrochemicals and fuels * Crude oil (petroleum) is made up of compounds, which are made of hydrogen and carbon, they are called hydrocarbons. * Carbon is aelement that has many different functions. It can join up to make chains, branched chains, and rings. * The properties of hydrocarbon depend on the size of its molecules groups. * Groups of molecules that have similar properties are known as homologous series. Homologous series and compounds * Organic compounds, which havea similar groups of atomsand have similar properties are called the homologous series of compounds. * Organic compounds have: . Have same general formulae 2. Similar characteristics 3. Show a gradual increase in physical properties such as m.p (melting point) and b.m (boiling point). Examples: Alkanes: . Saturated compounds (don't have double bonds) 2. Have no double bonds 3. React by substitution reactions * Some alkanes are methane, ethane, propane, and butane * General formulae of alkanes: CxH2x + 2 Alkenes: . Have double bonds 2. Made of carbon and hydrogen 3. Unsaturated (have double bonds) 4. React by addition reactions * Some alkenes are ethane, propene * General formulae of alkenes isCxH2x * More reactive than alkanes because of the double bond Refining oil * In order to be useful crude oil has to be refined Refining involves 3 stages: . Separation 2.
Investigation into the energy released by burning alcohols
Investigation into the energy released by burning alcohols Aim The aim of my experiment is to investigate how much energy is released by 5 different alcohols when they are burnt. These are Methanol, Ethanol, Propanol, Butanol and Pentanol. Scientific Theory In the following experiment I will be investigating how much energy is given off when you burn an alcohol. The 5 alcohols I will be investigating are methanol, ethanol, propanol, butanol and pentanol. All of these are part of the homologous series and so they all contain the functional group O-H. Their structures can be shown as follows: Therefore the general formula for alcohols is: When each of these fuels is burnt they are all exothermic, combustion reactions. A balanced combustion equation for methanol would be CH3OH + 11/2 O2 ? CO2 + 2H2O. A combustion reaction is when the fuel burns in the oxygen in the air producing carbon dioxide and water. The combustion equation can be used to work out the energy given off by using bond calculations. The reactions are exothermic because they give off energy to the surroundings and so the energy released that I work out will be a negative number. The heat energy released can be worked out from an equation. The equation is heat energy = vol of liquid x heat capacity (4.2) x temp change. Once this has been worked out you can find out the kJ/mol
In this experiment, I plan to find out the difference in energy release between different sorts of alcohols. To do this I will test how much alcohol is required to increase the temperature of 100ml of water by 30 degrees Celsius.
Plan In this experiment, I plan to find out the difference in energy release between different sorts of alcohols. To do this I will test how much alcohol is required to increase the temperature of 100ml of water by 30 degrees Celsius. Obviously, many factors may affect my results, therefore making them less reliable. To improve my results, I will carry out some preliminary research to see if I can improve the reliability and accuracy. Please see attached preliminary work for details (sheet 2a). The preliminary work showed, in short, that it was beneficial to use an aluminium foil shield to reduce heat loss. I will set up my apparatus as shown below. To ensure my experiment is safe, I will sport goggles and comply with all of the normal laboratory requirements, such as not sitting on benches. To further my acknowledgement of safety, I will have to take care as one of the alcohols burns with a clear flame. I predict that, from observing my bond energy calculations (sheet 1a), the alcohol that will heat up the water in the least weight loss will be Butanol. This should be followed by Propanol, then Ethanol and finally, the alcohol that will grace us with most weight loss will be Methanol. This is also backed up by the secondary data I obtained from the data book. That is as follows: Methanol -715 kJ per mole Ethanol -1371 kJ per mole Propanol -2010 kJ per mole
If There Is a Relationship Between the Number of Carbon Atoms In Several Different Alcohols and the Heat of Combustion of Those Alcohols.
Planning Experimental Procedures Introduction In this experiment, I plan to discover if there is a relationship between the number of carbon atoms in several different alcohols and the heat of combustion of those alcohols. I would also like to discover the nature of the relationship(if there is one). For example: if the heat of combustion increases or decreases with the number of carbon atoms and by how much. Apparatus Retort stand, boss, clamp, tin can, water, six alcohols (methanol, ethanol, propanol, butanol, pentanol, hexanol.) in burners, Bunsen burner, heatproof mat, thermometer (0 - 100ºc), digital scales. Method . Set up the retort stand as shown above. 2. Record the starting temperature of the water (100ml). 3. Take the first alcohol - in a burner - and weigh it on digital scales. Record the weight. 4. Light the wick on the burner and allow it to burn until the temperature of the water in the can has risen by 20ºc. WEAR GOGGLES AS HEAT IS BEING USED! 5. Re-weigh the burner and record its new weight. 6. Calculate the change in weight since lighting. 7. Repeat steps 2 - 6 twice more. 8. Repeat steps 2 - 7 for each of the other alcohols. Variables and Constants My variable will be:- number of carbon atoms present in the alcohol being tested. My constants will be:- increase in temperature. volume of water to be heated. Preliminary Experiment We were
Salters Open Book 2008 Fission and Fusion
Chemistry (Salters) Open Book 2008 Main differences between alpha and beta decay Alpha decay occurs when an unstable and heavy nucleus forms a more stable and lighter nucleus by disintegrating and emitting an alpha particle. (42? which is equal to 42He) This alpha particle contains two protons and two neutrons. Take for example 241Am, which is used in a smoke detector. The nuclear equation looks like this: 24195 Am 23793 Np + 42He Beta decay occurs when a neutron-rich isotope is changed into one with the atomic number one unit higher. This happens when a neutron is converted to a proton and electron. The electron is then released as Beta particle (0-1ß which means the same as 0-1e-) Take for example 23191Pa, the nuclear equation for Beta decay looks like this: 23191Pa 23192U + 0-1e- Due to the different events and reactions that occur, different products are formed. Here is a demonstration using 22588 Ra. ?-Decay 22588 Ra 22086 Rn + 42 He ß-Decay 22588 Ra 22589 Ac + 0-1e- Nuclear fission differs from natural radioactive decay. Radioactive decay and nuclear fission differ in many ways including the ways that the reactions must be started and the type of products that are formed. Radioactive decay has a lower energy barrier than fission and therefore is more common. Nuclear Fission involves the absorption of one neutron, whereas radioactive decay does
Enthalpy of Combustion of Alcohols
Chemistry Coursework Investigation Enthalpy of Combustion of Alcohols Procedure . Put 150³ of cold water in an aluminium calorimeter and record its temperature. 2. Support the calorimeter over a spirit burner containing the ethanol you are going to burn. Arrange a suitable draft exclusion system to reduce heat loss. 3. Weigh the burner and Alcohol. 4. Replace the burner under the calorimeter and light the wick. 5. Stir the water with a thermometer. 6. When the water temperature has risen by between 15 and 20ºC extinguish the burner but continue to stir it until the temperature stops rising. Record the highest temperature reached. 7. Reweigh the burner to find the mass of the alcohol that has been burned. 8. Repeat the experiment at least once more. 9. Now repeat the whole experiment 2 times but you have to use Methanol the first time and Butanol the second time instead of Ethanol. Aim: The aim for this experiment is to find the Enthalpy of combustion of 3 different alcohols Ethanol, Methanol and Butanol by doing that I'm going to prove my theory. How I will collect valid results in my planned experiment I am planning was to do the experiment I will be very carfully in following the procedure I always will be wearing impervious clothing.I will be tryingto keep the wind as low as possible by