Discussion
Table 1 summarises the results from the primary data collected. Figure 5 indicates there is a linear relationship between the molecular weight and heats of combustion. Figure 6 compares the heats of combustion of the primary data, the accepted values and values calculated from the bond dissociation energy. Figure 6 compares the heat of combustion values identified by the bond dissociation energy calculations, the accepted values and experimental values when 80g of water is heated by 10°C. The bond dissociation energies do not take into account the hydrogen bonding and the accurate energy required to change the tested alkanol from an aqueous state to a gaseous state. The experiments done to identify the accepted values were conducted
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With the use of standard deviation formulae, outliers have been determined.
Equation 1: standard deviation Outliers of 272.82kJ/mol in 1-Butanol, 433.71kJ/mol in 1-pentanol, and 702.73kJ/mol and 1142.7kJ/mol in 1-hexanol have been classified. These outliers could have been caused by any of the factors mentioned above.
To improve the experiment, the methodology could be improved by having an efficient calorimeter to retain as much heat as possible, rather than just a tin can. Additionally, more trials for each of the experiments could be conducted to ensure correct and precise data is collected to determine more accurate conclusions.
Conclusion
From the data analysed, a clear trend is seen. As the amount of carbon chains (and consequently molar mass) increases, so does the heat of combustion released. The hypothesis was stated as: “because 1-hexanol has more carbon bonds, it will produce the most amount of heat in the shortest period of time. By following the same reasoning, it is suggested that 1-hexanol will be followed by 1-pentanol and 1-butanol, respectively.” The experimental values show there is a linear relationship between the carbon chains and molecular weight, and the heat of combustion
One possible source of error that can affect the results was that a mercury thermometer was used instead of an electronic one. The use of a mercury
The boiling point elevation constant for water that was experimentally determined in this analysis was 0.4396 °C/m, which was derived from the slope of the trend line in Figure 2. This is slightly lower than the constant provided in lecture of 0.51 °C/m. This could be due to further evaporation of water from the solutions tested via refractive index after the boiling temperature was recorded.
I notice that angle H is in the opposite of the right angle and therefore angle H has a value of 90 degrees. This will mean that the sum of the angles that are listed as (8m - 18) and (5p + 2) will add up to 90. And since the angle (7m + 3) is opposite to the (5p + 2) angle, they're equal. Therefore (8m - 18) + (7m +3) = 90.
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:
Abstract: The identification and characterization of unknowns are an important part of organic chemistry. It is fundamental to know experimental methods to deductively identify compounds (1) . The determination of unknown #6 (2-butanol) was identified by a series of test; first taking the boiling point (94-96 C), performing a solubility test, Beilstien test, Ignition test, and the appropriate functional group tests. An infrared spectrum and an NMR spectrum were then obtained and confirmation of the compound was proved.
For instance, pentan-1-ol, the alcohol utilised to synthesis 1-pentyl ethanoate, is relatively flammable due to the hydroxyl functional group attached to the molecule. Therefore, in order to prevent severe burns, a laboratory coat and safety glasses were worn. The experiment was additionally performed whilst standing up, so that if the aliquot of pentan-1-ol ignited,
PODEn compounds are the synthetic product of methylal and methyl alcohol [31], and their physicochemical properties vary as a function of n. According to literature [45], the combustion-induced pyrolysis process of dimethyl ether, (CH3OCH3) includes four sub-processes, namely a dehydrogenation reaction, the decomposition of the produced CH3OCH2 into CH2O, the production of HCO from CH2O, and finally the production of CO and CO2. PODE is a kind of ether, presenting a molecular structure, which is similar to dimethyl ether. The Guassian software was adopted for investigating the pyrolysis mechanisms of the free radicals produced during the dehydrogenation of PODE3 molecules. The transition stages in several main decomposition reactions and the related reaction rates were explored for developing the detailed mechanisms in future
One of our sources said that alcohol burns really good and produces little CO2 and no odor. According to our results, not only is it really efficient, but it had no odor nor did we notice the same amount of emissions as gas and diesel. The diesel performed the least, but research has shown that diesel performs greater with different engines. The engines are engineered to have better traction, thrust, etc. that makes the diesel better. So, gasoline was the only real competition for the alcohol. Gasoline lasted a little less than a minute and alcohol lasted a little more than a minute, and gas heated the water less than the alcohol. Gas is barely better per second, but long term alcohol performs better. The literature points to alcohol performing better and the next breakthrough in alternative
I am going to investigate the enthalpy change of combustion for the alcohol homologous series. I will investigate how alcohols with increasing number of carbons affect the enthalpy change when an alcohol goes under combustion.
We will be using 6 different fuels to heat up 100ml of water, and find out the changes of the temperature. We will measure the temperatures of the water before and after the experiment. We will burn heat the water for exactly 2 minutes, and check the changes in temperature. The change in temperature will allow us to work out the energy given off the fuel by using this formula:
The specific heat capacity of the calorimeter was calculated using the observed temperature change during combustion of benzoic acid and the literature value of the change in internal energy of benzene which was 26461J/g. The specific heat capacity was calculated to be 9.34kJ/K. The ΔT was calculated to be 1.3 ̊C using the equation 1 below in which t60 was 6.73min.
A chemical reaction, known as combustion, occurs in the car motor. A combustion reaction consists of a hydrocarbon reacting with oxygen (O2) to give the products carbon dioxide (CO2) and water (H2O). A hydrocarbon is a compound consisting simply of Hydrogen (H2) and Carbon (C), methane (CH4) and diesel (C12H23) are examples of a hydrocarbon. The chemical equation for a combustion reaction is as follows: Hydrocarbon + Oxygen Carbon Dioxide + Water. The combustion reaction of methane (CH4) is: CH4 (g) + 2O2 (g) CO2 (g) + 2H2O (l), the combustion reaction of ethane is: 2C2H6 (g) + 7O2 (g) 4 CO2 (g) + 6 H2O (l) and the combustion reaction for butane is 2C4H10 (g) +13O2 (g) 8CO2 (g) +10H2O (g). If combustion takes place internally, the engine is referred to as an internal combustion engine. A diesel engine is an example of this. Internal combustion engines convert the chemical energy in fuel to mechanical energy via an exothermic reaction.
A bomb calorimeter with the Parr design was used for the apparatus, which would lead to an experiment to measure temperature in degrees Celsius as time increased. Two different sample pellets were used, one being benzoic acid while the other was naphthalene. These measured findings were then used to determine the change in temperature for each experiment, which for benzoic acid…
Due to the local topography and climatology, Bio-fuels can be produced from various sources. Likewise every nation will have its own source. Kanuga oil is abundantly available in india but it 's not been used and if used it 's a great resource of energy. This study explores the potential alternate for diesel as fuel for automobiles and other industrial purposes. This study is focused on kanuga methyl esters performance and emission characteristics and comparing it with the traditional petroleum diesel. The fuels are used pure methyl ester and different blends of the methyl ester with diesel.
In modern years, consumption of waste is the most significant one before disposing to the land. There is attention in the growth of alternative technologies for recycling waste tyres. The recycling of tyres using pyrolysis is an attractive means to deal with this problem. The present work focused on to increase the properties of the pyrolytic oil including elemental composition, higher heating value(HHV),viscosity, flash point, density and distillation were find out using IS standards and evaluate with the diesel. The Gas chromatography–mass spectroscopy (GC–MS) and Fourier transform infrared spectroscopy (FT-IR) analysis results were discussed in this paper to characterized the composition of the pyrolytic oil. The most important