Comparing the Enthalpy Changes of Combustion of Different Alcohols :: Enthalpy

Comparing the henry Changes of Combustion of Different Alcohols becomeI will find the henry shift of combustion of a takings of alcoholsso that I can investigate how and why enthalpy dislodge is affected by molecular structure of the alcohol.OutlineI will use Methanol, Ethanol, Propanol and Butanol in the experiment.I will use these four because they should give me clear results, andthey range from short enchained to long-chained hydrocarbons, sopatterns should be easy to spot in the conclusion.Vari fitsMy independent variables argon- The type of alcohol (I will use ethanol, methanol, propanol and butanol)My dependant variables are- the specific heating capacity of water- Mass of water in grams- Change in temperature of waterMy control variables are- The change in temperature of water- 20..C- The mass of water. If this were changed then all the results would be wrong, because it would take different amounts of goose egg to heat different volumes of water- The distance fr om the bottom of the calorimeter to the top of the wick. differently different amounts of energy could escape each time making it an inequitable test.PlanFrom carrying out the follow experiment I will be able to find out theenthalpy change of each evoke I am testing. The enthalpy change ofcombustion of a arouse is the measure of energy transferred when onemole of fuel burns completely. I will use the fact that 42 Joules ofenergy are unavoidable to raise the temperature of 1 gram of water by 1C. Enthalpy change varies according to the following conditions temperature, pressure and concentration of solutions. Therefore I willuse a standard pressure of I atmosphere, a standard concentration of 1mol dm.3 and finally a specified temperature of. I will use theequation enthalpy change = cm..Tc- Specific heating capacity of waterm- Mass of water in gramsT- Change in temperature of waterI will then comparison the enthalpy changes and the types of molecularstructures and so I will able to out why enthalpy change is affectedby the molecular structure of the alcoholPredictionI predict that as the number of carbons in the alcohol is increased,the enthalpy of combustion also increases. The enthalpy change ofcombustion of alcohols increases as the length of the chain increases.This can be explained if we compare one alcohol with the next in theseries. The chain length increases with an asset of a CH2 group.When the alcohol is combusted what actually happens is the covalent alliances are broken, and new bond are formed.