How does the Relative Molecular Mass change in heat combustion of an alcohol? :: GCSE Chemistry Coursework Investigation

How does the Relative Molecular Mass change in estrus combustion of an intoxicant?PlanningIntroduction============As alcohol burns in air it go againsts out energy as heat and light. I amgoing to investigate how the energy proceeds of an alcohol in combustionchanges, with increased relative molecular mass, or RMM. RMM is thesum of the atomic crowd together of both atom in the molecule. Using thealcohols Methanol, Ethanol, Propan-1-ol, Butan-1-ol and Pentan-1-ol,I will plan, and complete an experiment that tests the predictionbelow.======================================================================Prediction And Theory=====================In the combustion of alcohols in air, the alcohol reacts with group Omolecules, to create carbon dioxide and water. Many bonds are brokenin the process using up energy. At the same time, the atoms reforminginto the new molecules of carbon dioxide and water give out energy. Inthe combustion of alcohols, the energy created, when forming bonds will always be to a greater extent that what is lost, when breaking bonds, this givesus excess energy. This energy is given out in the main as heat, but alsoas light and sound. As energy is given out it is called an exothermicreaction. If the opposite were true, it would be an endothermicreaction. It is never accomplishable to calculate exact energy change byexperimentation due to inaccuracies and energy waste, so we use bondenergy calculations give the exact notional energy change.Bond energy calculations show that the higher the RMM the more energywill be produced for the same weight of fuel (RMM is the sum of theatomic masses of every atom in the molecule). This is because as theRMM increases there are more atoms and therefore, more bonds to bebroken and then made. As, when burning alcohols, this process givesout energy, the more bonds go through this process, ie as the RMMincreases the more energy should be released. The calculations alsosuggest that for every carbon atom yo u add to the chain of an alcoholthe energy out should increase by618 Kj/mol. I predict then, that as the RMM goes up then the energychange will get increasingly more negative i.e. more energy is givenoff. The RMM will be proportional to the final energy created as bothshould increase by the same tour each time, (RMM by 14 as one C and2 H atoms are added, and the energy out by 618KJ/mol). This willtherefore force in a straight-line on the graph. The bond energycalculations show how much energy should be released, accounting forexperimental inaccuracies however, I expect the experimental output tobe considerably less.Proposed MethodI am going to test how the energy output per mole in the combustion of