The Heat Of Combustion For One Mole Of Alcohol.

1885 words - 8 pages

Chemistry courseworkMy aim is to find the molar heat of combustion of ethanol, propanol and butanol .I will also be comparing the experimental molar heat of combustion with the theoretical, using bound enthalpy's.Background informationI have found some information that will help me with my experiment. This text is all from www.webchem.netThe complete combustion of propane can be represented by the following equation:or we could redraw it to represent the bonds present:We now need to work out how many of each bond type we have broken.8xC-H2xC-C5xO=OAnd then how many bonds have been formed!6xC=O8xH-OSo using data tables we can look up then average bond enthalpies from, and calculate the enthalpy change of the reaction.Bond TypeAverage bond enthalpy /kJ mol-1C-H+413C-C+347O=O+498C=O+805H-O+464Notice they are all endothermic.So we can now do the sum, remember, sum of bonds broken - sum of bonds formed.DHr°= [(8x413)+(2x347)+(5x498)] - [(6x805)+(8x464)]= - 2054 kJ mol-1 The value for the enthalpy of combustion of propane from the data table is -2219kJ mol-1.This apparent error is due to fact that we use Average Bond Enthalpies in our calculations and the fact that the values above relate to the gaseous state, while the standard combustion state of water is liquid. If we allow for this, we get a value of -2226 kJ mol-1 which is pretty close to the value obtained above. The remaining difference must be down to the average bond enthalpy factor.Preliminary experimentsI will use trial experiments to find the optimum conditions to make sure the test is fair. From an experiment I have done in a previous year I know that a copper calorimeter is the most suitable container to use compared to a boiling tube and a beaker. We also know from our previous experiments that it is best to use a stirrer. So as we know we're going to use a stirrer and the copper calorimeter we can go on to find out the optimum height and if we should use a draft blocker.SafetyBefore I start any experiments I need to think about the safety of my self and others. First I will be using only butanol only for my preliminary experiments as it is the least flammable and so the safest. To extinguish the flam of the butanol burner I will all ways replace the lid never blowing it as if there we any butanol spilled on the outside of the burner it would catch alight. I will be standing for the full derision of the experiment so if any thing were to be spilled I would be able to move out the way quickly and easily. I shall ware goggles to protect my eyes and as my hair is long keep it tied back.Method to find the optimum height·I will first gather my apparatus: butanol burner, copper calorimeter, thermometer, clamp stand, measuring cylinder, stopwatch, heatproof mat, and goggles, then set them up·I measured out 25ml of water·I took the initial weight of the burner and the initial temp of the water·I lit the burner timed it for 2min stirring it every 30seconds and then...

Find Another Essay On The heat of combustion for one mole of alcohol.

Determining the Number of Moles of Water of Crystallization Associated With One Mole of Copper (II) Sulfate in a Hydrate CuSO4 * xH2O (s).

1810 words - 7 pages ) ~ 5Percentage of water in the sample of hydrate35.7 % (rounded to 3sf)Actual percentage of water in the hydrate36.1% (rounded to 3sf)Percent error in the experiment 1.11% (rounded to 3sf)CONCLUSION AND EVALUATION The data support the alternate hypothesis that in a hydrated copper (II) sulfate one mole of salt is combined with five moles of water. The possible explanation for the observations follows. When the salt is heated, the temperature of

The Evolution Of The Internal Combustion Engine

1620 words - 6 pages From the mid-1800s to today, the internal combustion engine is becoming more and more complex. From minor improvements, to total reconstruction; the internal combustion engine has changed greatly, and is still changing. By the 3000s, who knows what possibilities will await, but for one to understand the evolution of the internal combustion engine, they must be knowledgeable of the history, present, and future. What is internal combustion

The Process Of An Internal Combustion Engine

947 words - 4 pages Process Essay Process of a 4-stroke Internal Combustion Engine A common phrase that is heard whilst growing up is "curiosity killed the cat". This phrase might be true but; "ingenuity brought the cat back". Having a mindset in which giving up is never an option has plagued most inventors of the modern day, especially a high school drop out named Nikolaus August Otto, born in 1832. Otto was responsible for the development and

Combustion Of Alcohols

2233 words - 9 pages transferred from one ion to another, so there is an electrostatic force between the ions.The variables that must be controlled are:* Mass of water* Amount of wick on burner* Type of alcohol* Height of can above flame* Type of can* Time of burningThe alcohols used in this experiment will be from methanol, to hexanol, their formulas and predicted enthalpy changes are:Substance Formula - Predicted enthalpy change (KJ/mole)Alcohol CnH2n+1OHMethanol CH3OH

An Investigation into the Enthalpies of the Combustion of Alcohols

5145 words - 21 pages the copper calorimeter tin from the alcohol burning by using the following formula: Heat given out(J) = mass of water(g) x 4.2(specific heat capacity of water) x change in temperature(oC) Then after working out the number of moles for each alcohol and then will use this and the calculation for heat energy given out to determine the energy given out per mole. Results: I tested each alcohol twice. Butanol was not tested as it was

Comparing The Enthalpy Changes Of Combustion Of Different Alcohols.

3350 words - 13 pages Plan:Aim:The enthalpy change of combustion of a fuel is a measure of the energy transferred when one mole of fuel burns completely. A value for the enthalpy change can be obtained by using the burning fuel to heat water and using fact that 4.2j of energy are required to raise the temperature of 1g of water by 1oC. In this investigation my aim is to find the enthalpy change of combustion of a number of alcohols so that I can investigate how and

Comparing the Enthalpy Changes of Combustion of Different Alcohols

4459 words - 18 pages thermometer has. Analysing evidence and drawing conclusions. Calculations. Now that I have my results, I will work out the enthalpy change of combustion (Hc) for each alcohol. I will work out the Hc for each replicate for each alcohol and then work out the average Hc. Here is an example of how I will work out the Hc. I will use replicate one of Methanol. 1. It takes 4.2J of energy to heat 1g of water by 1°C. So the amount of energy taken in by the

Efficiency of Internal Combustion Engine

1285 words - 5 pages system is same with turbo. Intercoolers increase the efficiency of the induction system by reducing induction air heat created by the supercharger or turbocharger and promoting more thorough combustion. (Wikipedia) The other known system is NOS (Nitrous Oxide System). Nitrous Oxide was first discovered in 1793 by the English scientist and clergyman Joseph Priestley. This system is used for specific cars like race cars. This system is formed

The Heat Death Of The Universe

1115 words - 4 pages that 'Sarah Boyle is never quite sure how many children she has'; (196). This comment leaves the reader confused and, in addition to the numerous derogatory and confusing references made to children throughout the story, causes the reader to think that she doesn't care for her children at all. Looking at some of the statements she makes, this is quite possible. In one situation she conceives the idea that a cereal may cause cancer, 'Perhaps

The Banning of Alcohol

1463 words - 6 pages decreasing. According to the National Highway Traffic Safety Administration statistics in 2011, the amount of 9,878 people died in drunk driving crashes, one every 53 minutes. Alcohol should be banned because alcohol is a really dangerous beverage which has brought a lot of sorrow and tragic stories to a lot of people’s lives and families, through driving, partying and making bad decisions. Alcohol in the form of alcoholic beverages has been

The Effects of Alcohol

2133 words - 9 pages beverages to our body?In order to understand how alcohol is broken down in our body, we need to understand what alcohol is. Ethanol is the type of alcohol found in alcoholic beverages and is diluted with water and other substances. It is considered a drug because the body builds up an increasing tolerance to it and develops a craving for it. Alcohol is a lipid-soluble compound and it can diffuse into the cells of our body and affect their function

Similar Essays

To Detemine The Heat Of Combustion Of Ethanol And Methanol. Procedures And Conclusion.

1358 words - 5 pages ethanol because, the heat of combustion of ethanol is 1367 KJ/mole, ignition temperature of 363oC and flash point of 13 oC. Whereas Methanol's heat of combustion is 724 KJ/mole, ignition temperature of 455oC and flash point of 12 oC.Since ethanol has a higher heat of combustion you would need to use 3 times the amount of methanol to get the same amount of energy produced from ethanol. Although ethanol has a lower ignition temperature then methanol, it

The Combustion Of Polymers Essay

1756 words - 8 pages transfers from one carbon to another forming a methylated end and a terminal alkene and second and more important the production of a free radical species. These products severe as the volatile small molecular weight carbon species that are needed for the gas phase combustion to occur. There exists two mechanisms a material can retard fire. The first is by physically impeding the fire. Materials might decompose to cool the polymer and produce a gas

The Combustion Of Alcohols Investgation: Investigate The Heat Energy In A Range Of Alcohol's Used As Fuels.

1219 words - 5 pages accurate.1. Heat which never enters the water, because of draughts, for example.2. Heat loss from the top and sides of the beaker.3. Heat which is not conducted by the beaker.4. Incomplete combustion - there is a restricted supply of oxygen, the alcohol was burning with an orange flame rather than blue. Some of the alcohol did not burn completely, giving carbon and carbon monoxide rather than carbon dioxide. A carbon deposit (soot) on the bottom of the

The Change In Enthalpy For The Combustion Of Magnesium Metal

1139 words - 5 pages The change in enthalpy for the combustion of magnesium metal Abstract ======== Hess’s law of heat summation states that the value of DH for a reaction is the same whether it occurs directly or as a series of steps. This principle was used to determine the change in enthalpy for a highly exothermic reaction, the combustion of magnesium metal. Enthalpy changes for the reactions of Mg in HCl (aq) and MgO (s) in HCl (aq) were determined