Enthalpies of combustion.
Enthalpies of combustion In this experiment we are trying to see how the enthalpies of combustion change with 4 different alcohols. The alcohols we will be using are. ?Methanol (CH3OH) ?Ethanol (C2H5OH) ?Propanol (C3H7OH) ?Butanol (C4H9OH) As you can see all of these alcohols are made out of the same compounds. What we want to know is how the number of Carbon atoms (C) affects the enthalpy of combustion. We set up the apparatus as shown above. We put a thermometer in and measured the temperature of the water. The alcohol was weighed and put under the beaker. The wick was set alight and we watched until the temperature had gone up approximately 10oC, extinguished the alcohol with the lid of the spirit lamp, took it to the front and weighed it again. We then went back to our benches and recorded the final temperature as well. We put all of these in a table so that when we took it home we could record it on the computer. We put them all down into a spreadsheet on the computer and worked out the temperature rise per. Gram of alcohol used. We repeated each run twice. This is what the table looked like: Alcohol Initial Temp. (oC) Final temp. (oC) Temp. Change (oC) Initial weight (g) Final weight (g) Mass used (g) Temp. rise/gm used Methanol 20 35 5 82.58 81.99 0.59 25.42372881 Methanol 20 33 3 81.99 81.49 0.5 26 Ethanol 20 33 3 93.14 92.91
Measuring the Enthalpy Change of Combustion of Different Fuels
Measuring the Enthalpy Change of Combustion of Different Fuels Kristen Schroeder Table of Contents . Apparatus and Materials 2. Equipment 3. Procedure 4. Risk Assessment 5. Explanation and sources 6. Data 7. Data Analysis, Amount of Heat Absorbed by the Water 8. Calculating Enthalpy Changes 9. Conclusion 0. Evaluation 1. Procedure Assessment Materials and Apparatus Chemicals Chemicals Empirical Formulas Molecular Structure Methanol CH3OH H O H - C - H H Ethanol C2H5OH or CH3CH2OH H H H - C - C - O - H H H Propan-1-ol C3H7OH or CH3CH2CH2OH H H H H - C - C - C - O - H H H H Butan-1-ol C4H9OH or CH3CH2OCH2CH3 H H O H H H - C - C - C - C - H H H H H Apparatus Equipment * 2 bench mats * 10° C - 50° C thermometer * access to a balance * 1 draught shield * 1 small aluminium can * 4 spirit burners containing o methanol o ethanol o propan-1-ol o butan-1-ol * 100 ml of water (for each experiment) * 1 Bunsen burner * matches * tweezers * pipette * extra amounts of the chemicals * 100 cm3 measuring cylinder * splints (small and slim) pieces of wood Procedure . Take a spirit burner that is for methanol. If it is not full to the top, use tweezers to open the spirit burner and then use a pipette to place more methanol into the burner. 2. Place the spirit burner
Burning alcohols.
Adam El Shafei 10B 2/1/2004 Chemistry Practice Coursework Aim: My aim is to find out which fuel releases the most energy per gram measured by heating water. Scientific Theory: In this investigation I will be burning alcohols to heat up a beaker of water. I will be using five fuels: methanol, ethanol, propanol, butanol and hexane. These five fuels are members of the alcohol family. The alcohol molecules have a "backbone" of carbon atoms. Alcohols have a general formula C H OH. Alcohols are derived from an alkane by removing an -H and adding an -OH. Their carbon atoms are surrounded by hydrogen atoms. These fuels 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. This means that the reactant energy is higher than that of the product. Heat energy is transferred from the flame to the fuel, and the fuel then takes up this energy as it starts combustion. Heat is lost through convection to the surrounding air through the sides of the fuel burner, and from the boiling tube. Hot air rises and is replaced by cooler air in a convection current. The hot air then heats the glass boiling tube by conduction. The height of the flame from the base of the boiling tube will be directly related to how quickly the water heats up. If the flame is too near
To investigate the combustion of alcohols.
To investigate the combustion of alcohols Planning I am going to investigate what happens when I burn specific alcohols. Alcohols are a series of related organic molecules of a homologous series, where each member varies from another by having a different number of carbon and hydrogen molecules. The general formula of an alcohol is: CnH2n+1OH, where n is the number of Carbon atoms. The first in the series has n=1 end the second has n=2 and so on. The similarities in molecular structure make alcohols have physically and chemically similar properties. Which change up the series because of the additional atoms. The table below shows a general increase in melting points and boiling points as the number of carbon atoms increases (from advanced chemistry) Name Molecular Formula Structural Formula Melting Point Boiling Point Methanol CH3OH ? ? Ethanol C2H5OH -117 78 (Propan-1-ol) C3H7OH -126 97 (Butan-1-ol) C4H9OH -90 117 The names like propan-1-ol refer to the position of the -OH group on the carbon chain, the OH groups above are on the first Carbon atom, the "1" position, there is also a "2" position and in larger molecules possible more. This table shows that I should investigate a series of different alcohols in my investigation to get an accurate and wide scope. Ideally I would need at least 5 alcohols for a good range of results for
Methanol Basics
Methanol Methanol is the simplest alcohol, containing one carbon atom. It is a colorless, tasteless liquid with a very faint odor and is commonly known as "wood alcohol." Methanol is one of a number of fuels that could substitute for gasoline or diesel fuel in passenger cars, light trucks, and heavy-duty trucks and buses. It is also known as Methyl Alcohol. Why Consider Methanol? Methanol's physical and chemical characteristics result in several inherent advantages as an automotive fuel: ADVANTAGES * LOW POLLUTION Emissions from methanol cars are low in reactive hydrocarbons (which form smog) and in toxic compounds. Methanol-fueled trucks and buses emit almost no particulate matter (which cause smoke and odor, and can also be carcinogenic), and much less nitrogen oxides than their diesel-fueled counterparts. * FUEL SUPPLY Methanol can be manufactured from a variety of carbon-based feedstocks such as natural gas, coal, and biomass (e.g., wood). Use of methanol would diversify the country's fuel supply and reduce its dependence on imported petroleum. * FIRE SAFETY Methanol is much less flammable than gasoline and results in less severe fires when it does ignite. * HIGH PERFORMANCE Methanol is a high-octane fuel that offers excellent acceleration and vehicle power. * ECONOMICALLY ATTRACTIVE With economies of scale, methanol could be produced,
To Find Out Which of the Five Alcohol’s Makes the Best Fuel To Heat Water.
Investigation Aim: The aim of this investigation is to find out which of the five alcohol's makes the best fuel to heat water. Background Knowledge: Combustion - This is when you set alight a fuel to react it with oxygen. Complete Combustion - This happens when all of the fuel is combusted with the oxygen. A large/unlimited supply of oxygen is needed for Complete Combustion to take place. Incomplete Combustion - This happens when only some of the fuel is combusted with the oxygen. A blockage of fresh oxygen has prevented all harmless carbon dioxide gas from being formed and some poisonous carbon monoxide is formed. Organic Fuels - These are natural stores of chemical energy. When they are set alight they give off carbon dioxide and water. For complete combustion there should be enough oxygen available for the fuel to react with. An Endothermic Reaction is when more energy is needed to break bonds between atoms than is released when new bonds are made. An Exothermic Reaction is when more energy is given out in bond forming when compared to the amount of energy taken in to break the bonds between each atom. Oxidation (combustion) is an Exothermic Reaction. Preliminary Work: Aim: To find out how much the temperature changes of water of volume 40cm3 in two minutes after being heated by ethanol. Method: We will use the following equipment: Ethanol Alcohol Burner
The purpose of this lab is to identify two different unknown organic compounds, through investigating different chemical properties by various experiments. The chemicals could be alkanes (hexane), alkenes (hex-1-ene) or alcohols (methylpentan-1-ol or hexa
Identification of unknown organic compounds Mohit Parkash Elias Assaf Mr. Nicolas Chemistry B N2A IEGS Introduction; We are provided with three sample bottles each containing 5-10 cm3 of aqueous solutions. Two of the compounds are pure organic substances while one substance is a mixture of the two pure organic compounds. The pure substances provided could possibly be Hexane, Hex-1-ene, Hexan-1-ol or methylpentan-1-ol. Aim; The purpose of this lab is to identify two different unknown organic compounds, through investigating different chemical properties by various experiments. The chemicals could be alkanes (hexane), alkenes (hex-1-ene) or alcohols (methylpentan-1-ol or hexan-1ol). Background; Alkanes, alkenes and alcohols are all organic compounds with different chemical/physical properties. Different chemical properties give different reactions with other substances, and different physical properties are for instance boiling point, melting point and density. By testing for their properties it is possible to determine what an unknown organic compound is. Alkenes are very useful compounds that can be used for fuel and illuminant, for the manufacture of a variety of polymers and as raw material for the manufacture of industrial chemicals such as alcohols etc. Alkanes are very useful compounds that can be used in the production of polymers and fuels. The
Find the heat of combustion of water.
Heat of Combustion Aim: The aim of the experiment is the find the heat of combustion of water. Hypothesis: The heat of the combustion for water will be 6510.77 J This is hypothesised by using the following equation: Heat in joules = grams water heated x temp rise (°C) x 4.2J/g°C. Theory: The heat of combustion of a substance is the heat liberated when one mole of the substance undergoes complete combustion with oxygen at a constant pressure of one atmosphere with the final products being carbon dioxide gas and liquid water. The heat of combustion is minus the enthalpy change for the combustion process, because ?H is defined as the heat gained. Combustion is burning, because a fuel combines with an oxidant (usually O2) and a sustained chemical reaction proceeds at a temperature above that of the surroundings or an oxidation process in which at least one reactant is gas and which produces energy in the form of heat (and usually light). One way of measuring the heat produced by combustion is to use the heat to increase the temperature of water. Heat in joules = grams water heated x temp rise (°C) x 4.2J/g°C. Materials: Tin can glass rod Balance ring stand Thermometer Measuring cylinder Ethanol Small spirit burner Wick Procedure: . The apparatus was set up. 2. 88mL of water was measured and added to the tin can. 3. The burner was half-filled with
What is Nuclear Power.
What is Nuclear Power Like coal, oil and natural gas, uranium is an energy resource which must be processed through a series of steps to produce an efficient fuel for use in the generation of electricity. Each fuel has its own distinctive fuel cycle: however the uranium or 'nuclear fuel cycle' is more complex than the others. To prepare uranium for use in a nuclear reactor, it undergoes the steps of mining and milling, conversion, enrichment and fuel fabrication. These steps make up the 'front end' of the nuclear fuel cycle. After uranium has been used in a reactor to produce electricity it is known as 'spent fuel' and may undergo a further series of steps including temporary storage, reprocessing, and recycling before eventual disposal as waste. Collectively these steps are known as the 'back end' of the fuel cycle. The Nuclear Fuel Cycle Like coal, oil and natural gas, uranium is an energy resource which must be processed through a series of steps to produce an efficient fuel for use in the generation of electricity. Each fuel has its own distinctive fuel cycle: however the uranium or 'nuclear fuel cycle' is more complex than the others. To prepare uranium for use in a nuclear reactor, it undergoes the steps of mining and milling, conversion, enrichment and fuel fabrication. These steps make up the 'front end' of the nuclear fuel cycle. After uranium has been used in
Experiment to Measure the Heat of Combustion of Butanol.
Experiment to Measure the Heat of Combustion of Butanol Aim: To find out the heat of combustion of a specific alcohol (in this case, Butanol). Combustion is the energy released when 1 mole of a fuel burns in pure oxygen. Background Knowledge: An exothermic reaction gives out heat, because chemical energy is converted into heat energy. It is opposite to an endothermic reaction - one that takes in heat. When we burn a fuel, in this case Butanol, it is called combustion. Combustion usually takes place in the air when the fuel combines with oxygen. However, substances can be burned in other gases. Combustion does not usually happen spontaneously but is triggered by heat. Variables: There will be two independent variables, and these will be, that the temperature will be allowed to rise roughly 30ºC, and that the type of alcohol used in each case will differ. There will also be a dependant variable - the mass of the alcohol which will be burnt is unknown before the experiment takes place. The experiment will have control variables - using the same aluminium can for each experiment, and having the same volume of water, are factors that will be kept constant throughout. What Will Be Measured and How: The temperature of the water will be measured using a mercury thermometer, and the mass of the spirit lamp will be measured using electric scales. Also, the
