Preview

Resonance Energy of Naphthalene by Bomb Calorimetry

Powerful Essays
Open Document
Open Document
3241 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Resonance Energy of Naphthalene by Bomb Calorimetry
Experiment 3: Resonance Energy of Naphthalene by Bomb Calorimetry

Cameron Fowler
CHEM 457: Lab Section 4
Submitted: 11/4/10
Lab Group #3:
Michael Hyle
Neil Baranik
Tim Riley
Abstract:
The enthalpy of combustion of naphthalene was experimentally determined to be -5030.44 ± 78.98 kJ/mol which was a 2.5% error from the literature value of -5160 ± 20 kJ/mol.2 The theoretical enthalpy of combustion of solid naphthalene was calculated to be -6862.68 kJ/mol using bond energies for the gaseous molecules, the heat of vaporization of liquid water and the literature value of the heat of sublimation of naphthalene, which was 72 ± 4 kJ/mol.2 The absolute value of the difference between the theoretical heat of combustion and the literature value heat of combustion of naphthalene was 1702.68 ± 20 kJ/mol.2 This difference indicates that the resonance energy of naphthalene is very high and that its most stable configuration has a much lower energy than the unstable configuration that was combusted during this experiment. The results were obtained using bomb calorimetry where a sample was combusted in a bomb immersed in water, and the variations in water temperature were used to determine the heat of the combustion.
Introduction:
The resonance energy of a molecule is the difference in energy between the actual configuration of a molecule and that molecule’s most stable structure. It is useful to know the resonance energy of a species as it describes the difference between an experimentally determined heat of combustion and a theoretical one, calculated using bond energies with Hess’s Law.1 This comparison gives insight into how stable the molecules being combusted in the experiment are, as well as how the environment in which they were combusted differs from standard pressure and temperature. There were three distinct goals that were to be accomplished during this experiment. An experimental enthalpy of combustion of naphthalene was to be calculated and



References: (3) McMurry, J. Organic Chemistry, 5th ed., Brooks/Cole Publishing Co.: CA, 2000, p. 564-566.

You May Also Find These Documents Helpful

  • Good Essays

    Pentane Combustion Lab

    • 667 Words
    • 3 Pages

    Firstly to calculated a sample for heat of combustion (-∆H) the heat (Q) needs to be calculated. Using the first tests’ results.…

    • 667 Words
    • 3 Pages
    Good Essays
  • Good Essays

    The Molar Heat of Combustion of a substance is the heat liberated when 1 mole of the substance undergoes complete combustion with oxygen at standard atmospheric pressure, with the final products being carbon dioxide gas and liquid water. (Ref. “Conquering Chemistry, Roland Smith, 2005”)…

    • 2051 Words
    • 9 Pages
    Good Essays
  • Good Essays

    Analyzing thermodynamic properties of a reaction: Bomb calorimeters are being used to measure the output of heat energy of a system which includes, the enthalpy changes of a system meaning the enthalpy change of formation, combustion, neutralization and atomization. This careful analyzing of may reactions thermodynamic properties could result in convenience in the future as many future scientists utilize this information gathered readily.…

    • 505 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    Chem data booklet

    • 1432 Words
    • 6 Pages

    Values of molar enthalpy of combustion of some common fuels at 298 K and 101.3 kPa…

    • 1432 Words
    • 6 Pages
    Satisfactory Essays
  • Satisfactory Essays

    Each alcohol that was used had different amounts of carbon and hydrogen atoms, as the amount of atoms goes up the amount of energy the alcohol releases goes up also, for example Octan-1-ol (C8H17OH) was the most efficient with the highest calorific value of 16.4KJ where as Ethanol (CH3OH) has a calorific value of 7.5KJ. The aim of this experiment was to find out which alcohol burner was most efficient when heating up water, and which used the least amount of alcohol to heat up 1--cm3 of water around 15degrees higher than the starting temperature.…

    • 532 Words
    • 3 Pages
    Satisfactory Essays
  • Good Essays

    The experiment results fell a little out of range of the class average. The reliability of the experiment was high as most groups in the class results were consistent. The accuracy could have been improved by using digital thermometers and more accurate measuring cylinders and scales. Some or very little heat was lost from the metal cup due to surrounding environment. Also the position of the fuels source under the metal cup can affect the accuracy. As the condition of the experiments was kept the same for the groups, the experiment had a high…

    • 460 Words
    • 2 Pages
    Good Essays
  • Good Essays

    Thermochemistry

    • 2424 Words
    • 10 Pages

    Purpose: This lab taught procedures for determining heat of capacity of a calorimeter and measuring enthalpy of change for three reactions. It also enforced methods of analyzing data obtained through experimentation and calculating enthalpy. These procedures are used in the branch of thermodynamics known as thermochemistry which is the study of energy changes that accompany chemical reactions. Concepts from this lab can be used to determine the potential energy of a chemical reaction. Much of the energy people depend on comes from chemical reactions. For example, energy can be obtained by burning fuel, metabolizing of food or discharging a batter.…

    • 2424 Words
    • 10 Pages
    Good Essays
  • Good Essays

    For all 3 weeks, the calorimeter oval bucket (#13) was filled up with roughly 2.000 kg of DI water. The temperature of the water was roughly around room temperature (depending how long it was sitting in the room). The bucket was then placed in the calorimeter in a certain way. At the bottom of the bucket, there were 3 “dents” which were aligned with the dents at the bottom of the calorimeter jacket (#14). The oxygen combustion bomb (#15) was then opened and roughly 10 cm of the wire (metal wire provided by the instructor) was cut and attached to the arms of the cup so the pellet of choosing (which was either the Naphthalene or the Benzoic Acid) would ignite with the wire and thus causing the temperature to increase.…

    • 892 Words
    • 4 Pages
    Good Essays
  • Satisfactory Essays

    Acetylene Lab

    • 304 Words
    • 2 Pages

    Even though this experiment do not have a fully complete combustion, the investigators can still predict that the less volume of acetylene gas are in the test tube and more volume of oxygen gas are in the test tube, it will have a better chance to form a complete combustion. To improve the quality of the experiment, ensure to use precise measurement and make less human errors as possible or perform the experiment few more…

    • 304 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    In this investigation I will be burning alcohol 's to heat up a can of water. I will be burning four alcohol 's, methanol, ethanol, propanol and butanol. The aim is to find out how much energy is produced when burning these alcohols. Alcohol 's react with oxygen in the air to form water and carbon dioxide.…

    • 1368 Words
    • 14 Pages
    Good Essays
  • Good Essays

    We hypothesized that if we recorded a fuel with a high energy to low volume ratio, then the fuel would be a better substance to use commercially, because fuels need to have a high energy output and low storage volume to be used as fuel. Our hypothesis was proven correct, as this experiment allowed us to gain a better grasp on the concepts of enthalpy, heat capacity, and thermochemical reactions, all of which were necessary for us to understand to complete the task. Paraffin wax produces more energy per gram than Ethanol based on our test results, and simply by the molecule comparison itself. Since Ethanol is an oxygenated molecule and already contains oxygen, it cannot burn at the same intensity as Paraffin does, since Paraffin is…

    • 320 Words
    • 2 Pages
    Good Essays
  • Satisfactory Essays

    science

    • 369 Words
    • 2 Pages

    Purpose: The purpose of this investigation is to use calorimetry to determine the molar enthalpy change in the combustion of each of a series of alcohols.…

    • 369 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Alcohol Combustion Plan

    • 1158 Words
    • 5 Pages

    In this experiment I will investigate the enthalpy changes of combustion. In particular I will be investigating the enthalpy change of combustion for different alcohols. I hope to investigate some of the homologous series alcohols, as well as a few structural isomers of these alcohols.…

    • 1158 Words
    • 5 Pages
    Good Essays
  • Good Essays

    Determination of Enthalpy

    • 1206 Words
    • 5 Pages

    In this experiment, you will measure the temperature change of two reactions, and use Hess’s law to determine the enthalpy change, ΔH of a third reaction. You will use a Styrofoam cup nested in a beaker as a calorimeter, as shown in Figure 1. For purposes of this experiment, you may assume that the heat loss to the calorimeter and the surrounding air is negligible.…

    • 1206 Words
    • 5 Pages
    Good Essays
  • Good Essays

    Calorimetry Experiment

    • 410 Words
    • 2 Pages

    I was able to conclude that my calorimetric constant for this calorimeter is 95J/g C.…

    • 410 Words
    • 2 Pages
    Good Essays

Related Topics