Is most efficient at heating water Essay

This was done by counting the number of polar bonds gloomy i. e. C-H and using a info table to find come forward the measurement of sinew required. Secondly, I worked out the energy released by bonds be make again by counting the bonds and using a entropy table. I subtracted the second number from the world-class to work out the energy released by the alcohol. Methanol Balanced Equation CH3OH+1. 5O2>CO2+2H2O Bonds resolveed east northeastrgy postulate for Bond Breaking (kJ/mol) Bonds do null Released from Bonds Made (kJ/mol).Total Ene Bonds Broken zero Required for Bond Breaking (kJ/mol) Bonds Made zip Released from Bonds Made (kJ/mol) Total Energy Used + 12383 kJ/mol Total Energy Released 15398 kJ/mol Total Molar Energy of Combustion.Heptanol Balanced Equation  Bonds Broken Energy Required for Bond Breaking (kJ/mol) Bonds Made Energy Released from Bonds Made (kJ/mol)Total Energy Used + 14299 kJ/mol Total Energy Released.-Bonds Broken Energy Required for Bo nd Breaking (kJ/mol) Bonds Made Energy Released from Bonds Made (kJ/mol) 1/mol Total Molar Energy of Combustion, ? H (kJ/mol) = +16215-20222= -4007 This data justifies my hypothesis. to a greater extent than energy is released as you go up the series of alcohols therefore the body of urine will cacoethes up by a given temperature with slight(prenominal) alcohol being burnt. GCSE CHEMISTRY COURSEWORK Obtaining While obtaining evidence I took into cast many safety points into consideration  Safety goggles were worn at all times I stood up so I could cursorily move out of the way if there were any spillages etc. I tucked my tie in my shirt to avoid it catching plan of attack I also made sure I took accurate readings by Stirring the water to maintain an even temperature  Closing windows that might arrest a draught  Keeping the tin at the same heyday above the flame.Repeating anomalous results GCSE CHEMISTRY COURSEWORK Analysing To produce a chart of molecular mess hall versus enthalpy of combustion both these determine lack to be calculated. Here is an example First, the energy released has to be calculated. This can be done using the following saying q=energy released m=mass of water (g) c=specific heat capacity of the liquid change (4. 18J/g/i?? c for water) ?t=temperature change of water For my first piece of data this is how q would be calculated. Temperature Change 10. 5i?? c Mass of pissing 400g (remember that water has a mass of 1g per cm3) Using the formula q=4004. 1810. 5.Second, the molar heat of combustion must be calculated. This can be done using the following formula -q=total energy transferred to the water (negative because the reaction is exothermic) n=number of moles (weight difference/formula mass) x1000=convert Js to kJs Continuing with the same example Energy Released 17556J (this was worked out with the first equation) Weight Change 1. 20g Formula Mass 32g Using the formula ? HMy original hypothesis was that as you g o up the series of alcohols, less of the alcohol will have to be burnt for the given temperature rise.My results turn up this hypothesis. The graph shows strong positive correlation proving that less alcohol is call for for the temperature rise as you go up the group. There are no anomalies, and there is hardly any scatter. When I compare my observational data with my theoretical value I can see that although my try outal set follow the same trend, they show much less energy being given off per mole than the theoretical ones. This is because not all of the energy produced went into the water (explained in more detail in the evaluation). GCSE CHEMISTRY COURSEWORK Evaluation.My experimental data agreed with the theoretically predicted values. When both sets of results were plotted onto a scatter graph, I could see that they both followed the same trend. However, the line representing the theoretically predicted values was lower down on the graph showing that the experimental valu es were lower than the predicted ones. This is because of the experimental errors detailed below. Reliability I believe my data to be certain. There is hardly any scatter as the results were cockeyed to the line, and there were no anomalies.The data was reliable enough to firmly advocate my conclusion. The fact that there was not much scatter shows this. However, the data was reliable but inaccurate because of the problems outlined below. If the data obtained was completely accurate thence it would be on the theoretical data line. Experimental errors It was impossible to nettle all the energy of the burning alcohol, using our equipment, into the can. Some inevitably escape around the can and into the room. This explains why our results showed slightly more alcohol needing to be burned than the theoretical amount.Sources of experimental error  Not all heat getting into the water (most escaped around the can or het up the can)  Draughts blowing in from outside Modificatio ns If I was to do this experiment again I might either use a different calorimeter than a tin can i. e. one that conducted heat into the water more efficiently or simply put a lid on the can and insulate it. I would also do the experiment in an environment out of the open air to stop air currents ever-changing my results and to concentrate the heat onto the water, rather than the air around.Further Work I might do the same experiment but using alkanes quite of alcohols. I would investigate as to whether they produce the same trend as with alcohols and see whether they are more or less efficient.  GCSE Chemistry Coursework 1 Show preview only The above preview is unformatted text This scholarly person written piece of work is one of many that can be found in our GCSE Patterns of Behaviour section.