Experiment: Testing The Heat of Combustion and The Energy Required to Combust Alcohol

The experiment began by mixing the initial 1.775g isopentyl alcohol with 2.3 mL acetic acid and about 5 drops sulfuric acid. This reaction mixture was then heated under reflux for an hour after boiling of the reaction mixture began.

The second method was using Hess’s law to add the accepted ΔHrxn 1 and flipped ΔHrxn 2 values of the net ionic equations. The same ΔHrxn 3 was obtained from both methods, 52.22 kJ/mol, and was defined as the accepted value. The third method used was performing reaction 3 in a calorimeter, measuring ΔT, and then finding q to obtain ΔHrxn 3. The value obtained from this method was 56.1 kJ/mol. The fourth method was explained in the previous paragraph: by appropriately adding up the measured ΔHrxn 1 and ΔHrxn 2 using Hess’s Law. The ΔHrxn 3 obtained from this method was -54 kJ/mol. The ΔHrxn 3 obtained from the fourth method was more accurate, as it had a 3.4% error from the accepted value, while the ΔHrxn 3 from the third method had an 8.4% error from the accepted value. Both ΔHrxn 3, however, can be considered to be reasonably accurate, as it was within 15% of the accepted value. To improve the results, a more accurate volume measuring instrument, such as a pipette, could have been used to dilute the reactants. This would result in the actual number of moles participating in the reaction becoming closer to the number used in calculation, thus resulting in a more accurate ΔHrxn. In addition, a more insulated calorimeter could have been used to reduce the amount of unaccounted heat escaping, allowing a more confident q measurement.

These experiments were established to find which fuel, out of Pentane, Propan-1-ol and Propan-2-ol would be the most suitable to take on a camping trip to cook with.

The aim of the experiment was to investigate a series of alcohols to then determine which was most efficient in releasing energy, from a mass/mole ratio. It can be hypothesized that as the number of carbon atoms in an alcohol increases the energy becomes greater. This is because as the number of carbon atoms increase the number of hydrogen atoms increase, this causes the molecular chain to become longer. As the molecular chain becomes longer it requires more energy to break down because there are more bonds to break than in a smaller chain. Therefore during combustion, the higher number of carbon atoms the more bonds it creates and the more energy it takes to break those bonds.

The purpose of this investigation is to burn selected alcohols of different molecular structure in a controlled environment to compare the magnitude and rates of energy release. Fuels are any kind of substance that, when burnt, produces chemical or nuclear energy that can be used for work. More accurately, fuels may be defined as a naturally occurring or artificially prepared combustible carbonaceous material (Palanna, 2009). One of the most common fuels that is still used today is charcoal. Charcoal is the remains of burnt wood which was discovered to be a good fuel source and was used to melt metals.

The study of alcohol as an academic experiment can be traced back to the 1700s when J.J. Plenc proposed the chemical identification of poisons (Center for Studies of Law in Action,

A 10 mL round-bottom flask was weighed both before and after approximately 1.5 mL of the given alcohol, 4-methyl-2-pentanol, was added. 3 mL of glacial acetic acid, one boiling chip, and 2-3 drops of concentrated sulfuric acid were added to the flask in that order. The reflux apparatus was assembled, the

Introduction Alkanols (Alcohols) are a homologous series in the hydroxyl functional group, meaning that they have an -OH. Carbon to carbon bonds within alkanol chains means that the boiling point of alkanols increases as the chain grows longer, this is because more energy is required to break the bonds between the carbon atoms. However, alkanols also experience hydrogen bonding meaning that not only are high amounts of energy needed to break the intramolecular bonds additional energy is needed to break the intermolecular bonds. Thus, alkanols have higher boiling points than their respective alkane. When the carbon to carbon bonds in alkanols break during combustion reactions they release energy, thus allowing for the use of alkanols, especially

In the experiment, I found that the reaction is a pseudo - first order reaction from analyzing the graph (Figure 2,3,4) and determine which were closer to a straight line. I found the pseudo- order kinetic rate constant that correspond to it is 0.0016 1/s because it was the slope of the straight line (Figure 3) Using this pseudo-order kinetic rate constant I found the real constant of the rate law by dividing the concentration of ethanol which gave us the constant to be 2.66×〖10〗^(-3) L/(mol s) .

After completing this experiment, it was evident that a few of our hypotheses were supported by the experimental data and some were not.

A variety of experiments were conducted in order to test the research hypothesis. Essentially, each of the experiments were performed to determine the consequences of low

Throughout the data collection period for this lab, the data that supported the hypothesis remained consistent for most of the lab, yet it was due to data

There were a few disadvantage observed with the use of only alcohols. One being, it became increasingly more difficult to burn alcohols as the molecules got bigger as more intermolecular force is needed to break the bonds. Another issue is the trouble and expense of modifying the engines for dual fuel capacity (Mithun Mohan,2015),(S.W. Mathewson.1980). In order to comply with the already existing diesel engines scientist resolved the issue with a blend of alcohol and diesel so only

Due to the array of variables that could have affected the experimental data over the course of the experiment it is hard to pinpoint with certainty the actual cause for the discrepancies. However, the reliability of the experiment could be improved majorly with one change. The experiment was conducting using the minimal amount of test repetition necessary to get the required results. If the test were to be completed, several tests for each concentration

A Combustion Test Facility comprises mainly of a furnace in which pulverized coal or any other form of fuel can be combusted and the flue gases produced can be analyzed via sample ports provided in the furnace. Since, it is a combustion test “facility”, it would also include proper setting up of that furnace on a mechanical structure so that the results of the flue gases (chemical results) could be analyzed properly and conveniently. An 80 kW Combustion Test Facility means that the heat capacity of the furnace is 80 kW.