Investigating The Energy Content Of Paraffin Essay

- Results: When liquid wax is exposed to the heat of a match, it transforms back into its original solid state.

Ratios of the reactants that are not the stoichiometric ratio provided by the balanced equation leave behind excess reactants. The stoichiometric ratios provided by the balanced equation prevent the formation of limiting and excess reactants for the exact amounts required are present and the reaction can be completed, yielding the most possible product and thus proving most effective. This combustion reaction is used to produce the explosive energy of the space shuttle and serve as a source of continuous energy for fuel cells in electric vehicles. In this lab, the same reaction was used to launch micro rockets off a launch pad to simulate the way explosive energy is generated to launch space shuttles. Fuel cells are electrochemical devices that make use of hydrogen and oxygen to produce electricity as well as water and heat as byproducts.

An Investigation into the Enthalpies of the Combustion of Alcohols = == == == ==

The experiment can also be done to compare the burn rate of different colored candles.

*Peanut oil has a higher smoke point and has less of a chance of burning during the experiment.

Because it is dangerous to burn magnesium, it is not possible to directly record heat change. Our lab team suggests an indirect way of determining the heat of combustion for magnesium. To accomplish this, we need to perform two separate trials. One uses a solid (powder) version of MgO, while the other uses Mg ribbon. With the results from these, we can use Hess’ Law to determine q=∆H. This provides both a safe and successful way of indirectly determining the heat of combustion for magnesium.

1. Place a small amount of wax from a birthday candle into a test tube. Heat gently over a burner flame until the wax melts completely; then allow

The atom of an element has electrons that are found around the nucleus in regions known as orbitals. When energy is absorbed by the electrons of an atom they begin to jump to higher energy levels. When this happens the electrons are in an excited state. However when the electrons begin to release the energy and drop in energy levels they emit electromagnetic radiation. If the radiation that is emitted falls between 400 to 700 nanometers then the electrons emit photons which we can see as visible light.

The burn rate of the mixture was recorded with a video camera and the results recorded and timed. The resulting footage was reviewed and the duration of the combustion noted on a tenth of a second basis. 4 grams of Alliant Green Dot double-base smokeless flake powder with no KClO4 added was also recorded twice in the same manner, to give a baseline burn time and averaged.

It was desired to compare a theoretical value of enthalpy of combustion to a literature value. To do this, the theoretical value was calculated using a literature value for the heat of sublimation of naphthalene, the heat of vaporization of water and average bond energies, given in Table 1 of the lab packet.1 Equations (1) and (5) were used to calculate the theoretical enthalpy of combustion of gaseous naphthalene, where n was the number of moles, m was the number of bonds, and ΔH was the average bond energy:

When the fuels are burnt, energy is given off. I will be calculating the energy given off using the formula above. The specific heat capacity is the energy

Introduction: The theory behind this experiment is the heat of a reaction (∆E) plus the work (W) done by a reaction is equal to

The aim of this experiment was to test the heat of combustion over a period of time, and the energy required to combust alcohols with different carbon chain levels. It was hypothesised that the higher the carbon chain of the alcohol present, the faster the heat of combustion will occur. Meaning more energy will be released for a higher carbon chain. After calculating the results from the experiment it was found that the hypothesis was partially supported. The reasoning for this is as the alcohol that posses a higher carbon chain, generally increased there reaction rates. However there were a few exceptions to this rule.

Purpose: To measure the heats of reaction for three related exothermic reactions and to verify Hess’s Law of Heat Summation.

UNIT – VI Mixtures of perfect Gases – Mole Fraction, Mass friction Gravimetric and volumetric Analysis – Dalton’s Law of partial pressure, Avogadro’s Laws of additive volumes – Mole fraction , Volume fraction and partial pressure, Equivalent Gas const. And Molecular Internal Energy, Enthalpy, sp. Heats and Entropy of Mixture of perfect Gases and Vapour, Atmospheric air - Psychrometric Properties – Dry bulb Temperature, Wet Bulb Temperature, Dew point Temperature, Thermodynamic Wet Bulb Temperature, Specific Humidity, Relative Humidity, saturated Air, Vapour pressure, Degree of saturation – Adiabatic Saturation , Carrier’s Equation – Psychrometric chart. UNIT - VII Power Cycles : Otto, Diesel, Dual Combustion cycles, Sterling Cycle, Atkinson Cycle, Ericcson Cycle, Lenoir Cycle – Description and representation on P–V and T-S diagram, Thermal Efficiency, Mean Effective Pressures on Air standard basis – comparison of Cycles. 4