Comparing The Enthalpy Change Of Combustion Of Different Alcohols

Comparison of Combustion of Different Alcohols The purpose of my experiment was to investigate the combustion enthalpy of a series of alcohols. The standard enthalpy of combustion is the enthalpy change that occurs when one mole of fuel burns completely in oxygen at 1 atmosphere and 298 K under standard conditions. All combustion reactions are exothermic, which is why all the values ​​of transformations that I expect to burn are always negative. I predict that the number of carbon atoms in alcohol molecules above ========== has an enthalpy of combustion variables that is done.

Investigate the change in the enthalpy of combustion of alcohol homologs. When carbon alcohol is burned, we study how alcohol with increased amount of carbon affects metamorphism. The energy released by alcohol when it is used is called the enthalpy of combustion. By using what I already have, I think alcohol with a large number of carbon atoms in the molecule will have greater alcohol change than alcohol with fewer carbon atoms. Therefore, as the molecular weight increases, I predict that the enthalpy of combustion increases.

Since a substance (fuel) releases energy by combustion (temperature rise), the combustion reaction is always exothermic, where the change of 焓 () is negative. All fuels for this experiment are a mixture of alcohol-ethanol, 1-pentanol and two different ratios (90%: 10%; 80%: 20%), which are the most common organic compounds is. Alcohols contain hydroxyl functional groups (--OH) attached to alkyl carbon atoms (Figure 1) (Chemwiki, 2014). The classification of alcohol depends on the number of carbon atoms attached to the carbon atom to which the OH group is attached. Both ethanol and 1-pentanol are primary alcohols () and only one carbon atom is attached to the OH group on the carbon atom (Chemiwiki, 2014). Secondary () alcohols and tertiary () alcohols are when 2 and 3 carbon atoms are attached to OH groups on carbon atoms, but they are not used in the experiment.

All combustion reactions from alcohol are exothermic, exotherm is the process of releasing heat, and in exothermic reaction the decrease in enthalpy of the reaction is negative. In the endothermic reaction, the increase in the enthalpy of the reaction system is positive. The enthalpy of the exothermic process becomes negative. Examples of exothermic processes are combustion reactions and neutralization reactions. I will guide myself with my plan, follow my plan and change my plan to get accurate results. At the beginning of the survey, I was not sure about the weather experimenting with the lid or lid. But after the preliminary test with the lid on the lid and covered with butan-1-ol, I got the following results: