Essay Investigating The Combustion Of Alcohols

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

Combustion of Alcohols

THE COMBUSTION OF ALCOHOLS

PROBLEM

Investigate the heat energy in a range of alcohol's used as fuels.

HYPOTHESIS

I predict that octanol will release the most heat energy. This is because there is more bond energy in that molecule than the other alcohols.

Within a molecule there are bond energies that are holding the atoms together. When the fuel combusts a chemical reaction takes place, this breaks the bonds, this requires energy, and makes new bonds this gives out energy. The energy differences between the two tell us how much energy was given out or taken in. We can show this on a graph.

ENERGY CHANGES DURING A REACTION

To find the bond energies in the molecule of the alcohol we have to look at the how much energy is in the separate bonds of the molecule. Below we have a table of bond energies.

Bond Bond Energy (kj/mol)

C - OH 402

C - H 435

C - C 347

H - O 464

C = O 805

If we draw out the structure of each molecule involved in the chemical reaction we can easily find out how much energy is in that molecule.

STRUCTURE OF THE MOLECULES INVOLVED

METHANOL

ETHANOL

PROPANOL

BUTANOL

PENTANOL

HEXANOL

HEPTANOL

OCTANOL

CARBON DIOXIDE

WATER

BALANCED EQUATIONS

If we work in the bond energies into these balanced equations, and we subtract the energy taken in by the breaking of the bonds from the energy given out by the formation of new bonds we will get the total energy released.

METHANOL

2CH3OH + 3O2(r) 2C02 + 4H20

ETHANOL

2C2H5OH + 6O2(r) 4C02 + 6H20

PROPANOL

2C3H5OH + 9O2(r) 6C02 + 8H20

BUTANOL

2C4H7OH + 12O2(r) 8C02 + 10H20

PENTANOL

2C5H9OH + 15O2(r) 10C02 + 12H20

HEXANOL

2C6H11OH + 18O2(r) 12C02 + 14H20

HEPTANOL

2C7H13OH + 21O2(r) 14C02 + 16H20

OCTANOL

2C8H15OH + 24O2(r) 16C02 + 18H20

We can see from the table above Octanol releases the most heat energy. This clearly shows that there is a correlation between the number of bonds in the molecules and how much total energy was released.

I also predict that the amount of heat energy released will increase with the number of carbon atoms in the alcohol. I can show this on a graph.

This graph shows us that the number of carbon atoms in the alcohol is directly proportional to the heat release. The line is a straight line and we can make a liner equation for this that links the number of carbon atoms to the heat released. This is,

Heat released = (-574 x No. of carbon atoms) x 2024

VARIABLES

My variables in my experiment will be the temperature of the water in the beaker and the mass of alcohol burnt. Things such as amount of water and how much the alcohol raises the water temperature must be controlled.

FAIR...

Loading: Checking Spelling

0%

Read more

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...

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...

Assess The Potential Of Three Sources Of Renewable Energy As Alternatives To Using Fossil Fuels

1793 words - 7 pages After experiencing the replacement of manual and animal labour by steam engines in the Industrial Revolution, cheap fossil fuels then became the main source of energy. However, faced with the notable increase demand for energy, fossil fuel, as a non-renewable resource becomes scarcer and more expensive nowadays. To solve this problem, the world needs to replace fossil fuels with other sources of energy which are relatively low-cost and more...

To detemine the heat of combustion of ethanol and methanol. Procedures and conclusion.

1358 words - 5 pages EXPERIMENTAIM: To determine the experimental heat of combustion of methanol (CH3OH) and ethanol (CH3CH2OH). To decide which would be a better choice to take on a camping trip.MATERIALS: 1 Copper container 1 Clamp1 Spirit Lamp with Wick Ethanol1 Retort Stand Methanol1 Box...

Experiment to investigate the heat released during a displacement reaction

1671 words - 7 pages PlanningIn this investigation I am going to investigate the various heat released during a displacement reaction when one factor, the variable, is changed. There are a number of variables which could be used in this experiment. You can change the metal used, the concentration of the metal salt, the amount of the metal, the type of metal salt, or the...

Why the Range of Indicators Used to Measure Development Has Increased in Recent Years

756 words - 3 pages Why the Range of Indicators Used to Measure Development Has Increased in Recent Years Essentially the ideology of development was based on a countries GNP this was down to Rostow’s Model; therefore the only indicator of development was a countries economy. The ideologies have changed and now there are a range of indicators that are used to classify a countries development such as social, demographic, hence including ...

Investigate and find the relationship between heat loss (of water) and surface area to volume ratio of animals.

1083 words - 4 pages To investigate the relationship between surface area : volume ratio and heat loss.INTRODUCTION:The aim of this experiment is to investigate and find the relationship between heat loss (of water) and surface area to volume ratio of animals. To investigate this, we are going to use three flasks of different volume (as the...

Sould Nuclear Power be Used as the Main Source of Energy

2023 words - 8 pages Should nuclear power be used as the main source of energy? This is a very controversial topic that will be discussed here. People from both sides of this issue all care about the environment, but have different opinions on nuclear energy. Before getting into the debate, it is important to know how nuclear power plants work. The nuclear reactor, which is usually twelve meters tall, is enclosed in a dome like building made up of meter thick...

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...

The Effect of Fossil Fuels on Biodiversity and Alternative Energy Resources

1498 words - 6 pages The Effect of Fossil Fuels on Biodiversity & Alternative Energy ResourcesFossil fuels are hydrocarbon deposits derived from the remains of ancient plants and animals under enormous amounts of heat and pressure. Oil, or petroleum, is one of the most common fossil fuels utilized by people all over the world on a daily basis. Crude oil is a smelly, yellow-black, viscous liquid composed of mostly nitrogen, oxygen, and sulfur, which is...

The Depletion of Fossil Fuels

1698 words - 7 pages Abstract— As the world began to raise concerns on climate change and rapid depletion of fossil fuels, there is a need to hasten the solutions for clean energy generation with renewable sources. Solar energy has the potential as an alternative source of energy as it is renewable, universally accessible and emits very low or zero CO2 gases. Solar photovoltaic (PV) system applications are suitable in Singapore due to its equatorial location, with...

Combustion Of Alcohols Essay

Combustion Of Alcohols

Planning

This investigation involves burning alcohol in the air. Key science- Chemistry by Eileen Ramsden says that " an alcohol is a series of organic, homologous compounds, with the general formula Cn H2n+1OH". The alcohol reacts with the oxygen in the air to form the products water and carbon dioxide:

Cn H2n+1OH +(n+n/2)-1O2 ? nH2O + nCO2

The structure of the molecules in this reaction is:

H H | | H - C - C - O- H + 3[O=O] ? 1/2[O=C=O] + 3[H-O-H] | | H H

This reaction is exothermic, as heat is given out. This is because the amount reactant energy is more than the product energy the difference between this is ?H, therefore some energy has been given out in the form of heat.The energy is given out when forming the bonds between the new water and carbon dioxide molecules. This can be shown in an energy level diagram: Reaction co-ordinate ?H is the heat content, which is the enthalpy, which is negative in exothermic reactions as the diagram shows that energy is 'lost' as heat. Enthalpy is defined as the energy of reaction, or the heat energy associated with a chemical change. Chemical Principles By Master & Slowinski says that "For any reaction carried out directly at a constant pressure, the heat flow is exactly equal to the difference between enthalpy of products and that of the reactants", or: Qp = Hp - Hr = ?H Where Qp is the heat flow at constant pressure, Hp is heat energy of products, and Hr is the heat energy of the reactants.

To measure ?H given off, we must use this energy to heat something, this will be water. This is assuming that all the heat produced by combustion of fuel (?H) will equal the amount of heat absorbed by the water (q). So I will measure the amount of energy required to do so. This can be worked out by useing the formula: q = mass X specific heat capacity X temperature rise 1000 Where q is the quantity of heat. The specific heat capacity is the amount of energy required to heat the substance, and is calculated using the formula q = MC?, where q is the enthalpy, is the specific heat capacity and ? is the temperature rise. I chose to use water as it is safe, easily obtainable, and has a constant, reliable specific heat capacity of 4.2J/?C.

The bonds which are made in a exothermic reaction "are forces of attraction between the atoms or ions in a substance" according to Key science- Chemistry by Eileen Ramsden. These can be of two types: covalent, in which the atoms share electrons. Examples of this are water and carbon dioxide, which has a double covalent bond because it shares two pairs of electrons are shared. The other type of bonds are ionic, where a metal is involved. This is where electrons are 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...

Loading: Checking Spelling

0%

Read more

Investigate the amount of energy released when different fuels burn

1382 words - 6 pages 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.The reaction that is involved in burning alcohols is exothermic because heat is given out. From this reason the reactant energy is...

Experimental Utilization Of 2-Ethoxy Ethyl Acetate

1404 words - 6 pages Introduction The diesel engine dominates the field of commercial transportation and agricultural machinery on account of its superior fuel efficiency. However they emit more emissions. The use of oxygenated fuels seems to be a promising solution towards reducing emissions in existing and future diesel engines. Oxygenated fuel is a chemical compound containing oxygen. It is used to help fuel burn more efficiently and cut down on some types of...

enthalpy change and fuel efficiency

1243 words - 5 pages Jean ZhangBest Fuel Lab: Comparing Enthalpy Changes ofDifferent Alcohols toDetermine Fuel EfficiencyIntroduction:The purpose of this experiment is to determine which of two types of alcohols, methanol (CH3OH) or ethanol (

Rauner

1243 words - 5 pages Jean ZhangBest Fuel Lab: Comparing Enthalpy Changes ofDifferent Alcohols toDetermine Fuel EfficiencyIntroduction:The purpose of this experiment is to determine which of two types of alcohols, methanol (CH3OH) or ethanol (

Fuel Cell Research

5842 words - 23 pages Ever since the beginning of time, mankind has been dependant on Mother Nature to provide them with various energy sources for cooking, staying warm, and powering machines. At first, this energy source was wood. Then, as technology increased, man found other things to burn, such as coal, oil and gas. As the need for greater energy sources increased, man started looking around them. They found water, light, and wind. Still in need of energy, man...

Alternative Fuels

3959 words - 16 pages Alternative Fuels Demand for gasoline has been the driving force in utilization and depletion of crude petroleum, which is a non-renewable resource. In recent years, tendencies have just begun to, at times, favor alternative fuels to power autos. Many possible alternative fuels exist, certainly not without their drawbacks. These alternatives include, but are not limited to, alcohols, gasohols, and both liquefied and gaseous natural gas, as...

Year 12 Chemistry: Production of Materials. Ethanol Research Task

1697 words - 7 pages Year 12 Chemistry Research Task9.2 - Production of MaterialsDescribe the dehydration of ethanol to ethylene and identify the need for a catalyst in this process and the catalyst used.A dehydration reaction is a reaction in which a molecule of water is removed from a compound. The molecule of water is released as one product.A hydrogen atom and

Alternative Fuels

5210 words - 21 pages over 40 sources - very comprehensive overview Omit Fuel Cells (not an alt fuel)Paxton King11&12*1995An Examination of Feasible Alternative Fuels IndustryPaxton King CPT-415Univ. DaytonDemand for gasoline has been the driving force in utilization and depletion of crude petroleum, which is a non-renewable resource. In recent years, tendencies have just begun to, at times, favor alternative fuels to...

Biodiesel Production Using Supercritical Methanol

1548 words - 6 pages A major part of all the energy produced worldwide comes from fossil fuel sources. These sources are limited and are depleting at a fast pace. The depletion of these fossil sources has led to the search of alternative fuels from renewable sources like plant biomass. Vegetable oil is one such renewable source. Vegetable oil has gained much attention in recent years since it has many environmental benefits and it can be obtained from renewable...

Is Biodiesel a Viable Alternative To Diesel From Fossil Fuels For Trucks And Buses?

1029 words - 4 pages 1.0 IntroductionBiodiesel is defined as mono-alky esters of long -chain fatty acid. It is a fuel that derived from the vegetable oils, animal fats, which is similar to the diesel fuel except that it is made from the crops. It is produced from domestically grown, renewable sources, such as crop oils or animal fats which are then chemically converted into biodiesel...

Alternative Fuel Vehicles You Can Buy Today

3802 words - 15 pages From the earliest days of the automotive industry alternative fuels have always competed with petroleum for powering vehicles. Nicholas Cugnot made the first self-powered road vehicle in 1769 with a steam engine, and the first gasoline automobile didn't appear until over 100 years later from Karl Benz. Through the late 19th and early 20th century...

0 thoughts on “Essay Investigating The Combustion Of Alcohols”

    -->

Leave a Comment

Your email address will not be published. Required fields are marked *