Electricity and Magnetism Essay Example for Free

Electricity and Magnetism EssayIn this investigation I result be desirous a range of inebriant in a method known as calorimetry. This will sp atomic number 18 me to see the amount of brawniness produced by each(prenominal) alcohol, and then look at the structure of the alcohol and investigate why an amount of slide fastener is produced for each alcohol. Before I go on with the try there are several factors that must be first understood. What is an alcohol? The definition of an alcohol as taken from Richard Harwoods Chemistry textbook is a series of organic compounds containing the functional group OH. The OH group, called a hydroxyl radical group is what defines the compound as an alcohol.The alcohol compounds are very similar to the alkanes, however alcohols contain unrivaled oxygen atom, creating the hydroxyl group, and making the alkane an alkanol (alcohol). As the hydroxyl group makes the compound different to an alkane, the hydroxyl group is seen to be function al. The formula for alcohol is In this investigation I will look at the first five alcohols. These are methanol, ethanol, propan-1-ol, butan-1-ol and pentan-1-ol.The classification of alcohols is similar to the classification of alkanes, where the name refers to the number of carbon atoms i. e.meth- maven carbon atom, eth-=two carbon atoms, prop-=3 carbon atoms, but-=four carbon atoms, pent-=five carbon atoms and so on. The carbon atom that the hydroxyl group is bonded to whitethorn classify the alcohol further. If it is joined to the end carbon atom it is classified as -1-ol, if it is bonded to the second carbon atom it is classified as -2-ol and so on. The five alcohols I am testing are shown with formulas, and atomic structure dia constant of gravitations be number 1 image RMM Formula expression Boiling Point Methanol.What is burn? The definition of conflagration as taken from Richard Harwoods Chemistry textbook is a chemical reaction in which a center reacts with oxygen the reaction is exothermic. Burning is a combustion reaction that produces a flare out. The reactions that will take place in our investigation will be combustion reactions, as we burn the alcohol in calorimetry. The combustion of an alcohol produces carbon dioxide and weewee. This is represented by the spare-time activity equation ALCOHOL + OXYGEN iCARBON DIOXIDE + WATER e. g. The combustion of methanol produces carbon dioxide and wet METHANOL + OXYGEN i CARBON DIOXIDE + WATER 2CH3OH + 3O2 i 2CO2 + 4H2O What is calorimetry? Calorimetry is defined as the science of heat. It may be used in chemistry to measure the heat energy exchanged for a substance during a reaction, by allowing the substance reacting to heat a careful jackpot of liquid. The temperature change of this liquid is measured and put down, and the following equation may be used to calculate the heat energy transferred to the liquid wake change = MC?T (where M = nap of liquid, C = critical temperature, and T = temperature change). The critical temperature is the residuum between heat energy applied and the subsequent temperature rise. E. g. for 1g of piddle a temperature rise of 1 i C requires 4. 8 joules of heat energy. Using calorimetry may be used to measure both reactions in solution, and reactions non in solution. Wet reactions or those in solution are more exact than those not in solution, as the actual energy release of the reaction is creation measured instantly as a thermometer is placed in the solution.For change reactions, (a reaction not in solution such as the burning of an alcohol) the reaction must be used to heat a passel of water and the temperature maturation measured from the water. As the combustion reaction must transfer its heat energy from the reaction to the water, calorimetry for dry reactions spate be inaccurate due to heat loss. HYPOTHESIS I believe that the increased complexity of a molecule and the energy released by it are proportional. I found t his idea upon the theory of open frame and making bonds. In a molecule, bonds hold atoms together.When these bonds are formed energy is given out to the environs (exothermic), and when these bonds are broken energy is absorbed from the milieu (endothermic). This may be seen by the alcohols boiling points Name Boiling Point Methanol 65 Ethanol 78 Propan-1-ol 97 Butan-1-ol 117 Pentan-1-ol 137 Using this theory of breaking/making bonds, we can say that there will be a greater amount of energy released from the combustion of a more complex alcohol, as more bonds will be formed. When more bonds are formed, more heat energy is released. The hypothesis may be seen on the flowing graph exam To investigate the relationship between the structure and heat provided by combustion of a range of alcohols, we will use the method of calorimetry. We will do this by burning an alcohol, and allowing it to heat a mass of water. amount the temperature rise of this mass of water we can use the formul a to find the heat energy released during the reaction. setup == 1 can == 1 measuring cylinder == Water == 1 thermometer == 1 stand == 1 clamp == 1 boss == 1 heat mat == 1 alcohol burner/candle == 1 balance == Draught shields Fig1 Experiment setup. Method.Safety must be ensured at all times, as passing flammable substances are being burned here. All students must wear eye protection during the experiment, handicap standing during the experiment, and be aware of the flames around them. 1. The apparatus is set up as shown in name 1. 2. The alcohol candle is weighed on the balance, and the mass recorded. 3. The mass of water in the can measured and recorded 4. The height between the candlewick, and the base of the can must be set and recorded, measuring the distance with a ruler. 5. The temperature of the water is measured and recorded using the thermometer.6. The candle is lit and the thermometer monitored until the water has risen by a given temperature. 7. The candle is blown ou t, the burned-over wax on the base removed of the candle, and the candle is weighed. The entropy produced by this method will then be calculated by the formulas ? H (j) = mass of water (g) X specific heat capacity of water (S. H. C) X temperature rise (? C) The result of this is found per gram of alcohol burnt by dividing it by the change of mass ? H per gram of alcohol burnt (J/g) = ? H (? C) / change in mass (g) The results of this are the found per mole of alcohol burnt.? H per gram of alcohol burnt per mole (J/mole) = ? H per gram of alcohol burnt (g) X RMM of alcohol Variables in that respect are two instances of versatiles dependant variables and in mutually beneficial variables. Dependant variables are those that are unbroken constant at a set value, so that they cannot cause variation in the results, by changing throughout the experiments. thither should only be one independent variable in a test, this is what is being tested. thus the dependent variables for this inv estigation are as follows (see fig 2) 1. The distance of the wick from the base of the canThe distance of the flame from the base of the can may variegate the results greatly, as it will decide how much of the flames heat is transferred directly to the can and to the water. The experiment should allow the flame to contact the can at its hottest point. The most accurate and inviolable way to measure flame distance from the can is to measure the distance of the wick. For the purposes of our experiment this should be accurate enough. Measuring the distance from the wick and the base of the can each time will control this variable. 2. The mass of water heated.The volume of water can vary the experiment greatly, as the greater the mass of water used, the more alcohol will be combusted to reach the target temperature. Also when a greater mass of water is used, the test will go on for longer, and thus a greater amount of energy will be transferred to the surroundings as wasted energy. Me asuring the amount of water used each time will control this variable. 3. The type of can used. The type metal the can is made from is super important to the experiment, as different metals conduct heat with different efficiency and at different rates.Therefore the type of can used will affect the heat transfer to the water. Using the same can each time will control this variable. 4. The heat increase The heat increase can vary the experiment, as the greater the energy increase, the greater the mass of alcohol burnt, and the greater amount of energy transferred to the surroundings as waste. The start temperature may affect the results, as the higher the temperature the equipment reaches, the more heat will be wasted in the surroundings, according to the theory that heat energy moves from areas of high heat energy to areas of low energy.By allowing the equipment to cool after each experiment to a set temperature this variable may be controlled. 5. Stirring of the water Stirring the water will affect the results, as it means that the whole mass accounted for in the calculation will be being heated, not just one volume of water. The type of stirring in terms of frequency and power may affect the results also, and must be kept constant. To control this variable, the same type of stirring will be used each time. The only variable in the experiment will be the changing type of alcohol being combusted, as this is what is being investigated.