Comparing the enthalpy changes of combustion of different alcohols

Comparing the enthalpy changes of combustion of different alcohols: Aim: The aim of my investigation is to compare the enthalpy changes of combustion of two chosen alcohols from the given list displayed: Alcohol name Molecular formula Structural formula Methanol CH3OH Ethanol C2H5OH Propan-1-ol C3H7OH Butan-1-ol C4H9OH Propan-2-ol C3H7OH Butan-2-ol C4H9OH 2-methylpropan-1-ol C4H9OH Alcohols are derivates of alkanes; they have similar structures but varying functional groups. In alcohols one of the hydrogen atoms, which is generally attached to one of the central carbons, is replaced by an -OH group (Hydroxyl group). This variation largely determines the behaviour of the members of this homologous series in certain reactions. For example, Alcohols tend to have higher boiling points than the respective alkanes; this is because although the hydrogen bonds between the molecules are relatively weak, they are stronger than other attractive forces between covalent molecules. I have chosen to compare the enthalpy change of combustion of Methanol, Ethanol Propan-1-ol and Butan-1-ol. This is because they are fairly commonly used, and a larger set of information is available about them. During combustion, the two alcohols will burn in a plentiful supply of oxygen, and the products of the combustion will be carbon dioxide (CO2) and water (H2 O). The elevated

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  • Level: GCSE
  • Subject: Science
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Comparing the Enthalpy Changes of Combustion of Different Alcohols.

Michael Taylor Comparing the Enthalpy Changes of Combustion of Different Alcohols: Planning Assessment The enthalpy change of combustion of a fuel is a measure of the energy transferred when a mole of the chosen fuel burns completely. The value for the enthalpy change in a fuel can be found by using the burning fuel to heat water and using the fact that 4.2J of energy are required to heat 1g of water by 1oC. In this activity I am going to find the enthalpy change of combustion for 5 alcohols: Methanol (CH3OH), Ethanol (C2H5OH), Propan-1-ol (C3H7OH), Propan-2-ol (C3H7OH) and Butan-1-ol (C4H9OH). I am doing this to investigate how molecular structure of a molecule affects its enthalpy change. Equipment List: - Spirit Burners containing: Methanol Ethanol Propan-1-ol Propan-2-ol Butan-1-ol - Small Copper Can or other metal container to act as a calorimeter - 0-110oC Thermometer - 50 cm3 Pipette + Pipette filler - Access to a balance - Bunsen Burner with Splints - Draught Shielding - Clamp Stand - Burn-Proof Matt - Distilled Water Plan: -Put 100 cm3 of water in the calorimeter and record its temperature. (The same temperature each time will produce the most accurate results.) -Record the weight of the Spirit Burner containing the alcohol you are testing. -Set the Calorimeter above the Spirit Burner using a Clamp Stand, just high enough for the flame to

  • Word count: 1293
  • Level: GCSE
  • Subject: Science
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Comparing the enthalpy changes of combustion of different alcohols

Kate McAllister 2 VK Chemistry Coursework Planning assessment- Comparing the enthalpy changes of combustion of different alcohols Aim: I am going to investigate the difference in enthalpy of combustion for a number of different alcohols. My aim is to find out how carbon chain length affects the enthalpy change that occurs during the combustion of alcohols. The enthalpy change of combustion of a fuel is a measure of the energy transferred when one mole of the fuel burns completely in oxygen. I will be able to calculate a value for enthalpy change by burning different fuels to heat a specific amount of water using the fact that 4.2J of energy are required to raise the temperature of 1g of water by 1oC. I will produce a wide range of results and will be able to compare them, calculate their enthalpy change of combustion and effectively find an answer my brief. Apparatus: Spirit burner (75 cm3) 500 ml copper can (diameter of 10 cm) with specially adapted lid Boss, clamp and retort stand Electronic balance (to 2 d.p.) Heatproof mat Goggles Measuring cylinder 100 cm3 Measuring cylinder 200 cm3 Mercury thermometer Insulation chamber Stirring propeller Distilled water Methanol (50 cm3 ) *3 Ethanol (50 cm3 ) *3 Propan-1-ol (50 cm3 ) *3 Butan-1-ol (50 cm3 ) *3 Pentan-1-ol (50 cm3 ) *3 Hexan-1-ol (50 cm3 ) *3 Hazard Cards Combustion is principally the

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  • Level: GCSE
  • Subject: Science
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Comparing the Enthalpy Changes of Combustion of Different Alcohols.

Comparing the Enthalpy Changes of Combustion of Different Alcohols Introduction The enthalpy change of combustion of a fuel is a measure of the energy transferred when one mole of the fuel burns completely. A value for the enthalpy change can be obtained by using the burning fuel to heat water. In this experiment I will be calculating and comparing the enthalpy changes of combustion of 5 different alcohols. I can calculate the enthalpy change by using the information that 4.2J of energy is needed to raise the temperature of a 1g of water by 1ºc. I will heat a measured volume of water using a fuel burner to change its temperature by 15ºC; then I will find the mass of the fuel that has been burnt. With this information I will be able to calculate the amount of energy in 1g of the fuel used. I will then plot my results into a graph, in order to compare them and to allow the pattern to become more apparent. Equipment * The apparatus required to carry out this experiment are as follows: * Heat proof mats (x6) * Clamp stand * Calorimeter * Fuel burners (containing Ethanol, Methanol, Propan-1-ol, Butan-1-ol, and Pentan-1-ol) * Scales * Water * Splints * Bunsen burner * Parcel tape * Thermometer * Calorimeter lid * Measuring cylinder * Scouring pad * Emery paper. Method To carry out this investigation, I started by placing all bags, coats and stools away

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  • Level: GCSE
  • Subject: Science
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Fertilisers are substances that supply plant nutrients or correct soil fertility

Fertilisers are substances that supply plant nutrients or correct soil fertility. They are the best way of increasing crop production and of improving the quality of food. Fertilisers are used to supplement nutrients in the soil, especially to correct yield-limiting factors, such as weather, space and water. The main nutrients in fertilisers are nitrogen, phosphorus, and potassium (these are the macro- nutrients) and other nutrients (micro nutrients) are added in smaller amounts. Fertilisers are usually applied to soil, or can be sprayed on leaves. Fertilisers usually provide, in different proportions: . Three main macro nutrients: nitrogen (N), phosphorus (P), and potassium (K). 2. Three secondary macro nutrients: calcium (Ca), sulphur (S), magnesium (Mg). 3. And trace minerals (micro nutrients): boron (B), chlorine (Cl), manganese (Mn), iron (Fe), zinc (Zn), copper (Cu), molybdenum (Mo) and selenium (Se). Without nitrogen, green plants would be weak and smaller than they should be. Phosphorus is vital to the growth and health of plants. It assists in converting the sun's energy and other chemicals (nitrogen) into usable food for plants. A phosphorus deficiency will lead to stunted looking plants that produce a lower quality fruit or flower. Potassium, often called potash, helps plants use water and resist drought. It promotes healthy

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  • Level: GCSE
  • Subject: Science
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Formation of Aspirin

Experiment No. 2: Preparation and Recrystallization of Aspirin Name: Afifah Mustaffa Admission No: 1106361 Date of experiment: 8 November 2011 Date of Submission: 23 November 2011 . Synopsis The objectives of this experiment were to familiarize students with the preparation of simple organic compounds and the process of recrystallisation to purify the compound. The experiment also allows students to conduct the synthesis of aspirin and also to enhance the students’ skills of recrystallisation and determining the melting point of a substance. . Introduction . History of Aspirin In the past, it was discovered that salicin, which contained salicyl alcohol, was a main component of willow bark. Salicin was also found to be an organic compound. Salicyl alcohol and salicylic acid can be derived from the hydrolysis and oxidation of salicin. Even though salicylic acid proved to be a better pain reliever as compared to salicin, it caused irritation to the membrane lining in the stomach. The phenol-OH group forms acetylsalicylic acid when it is converted into an ester. Acetylsalicylic acid, also known as aspirin, seemed to have less harmful side effects and it was also more effective as a painkiller as compared to salicylic acid. Aspirin, a type of salicylate, is a white, crystalline solid. Although it is only slightly ionized in the stomach, which has an acidic pH,

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  • Level: GCSE
  • Subject: Science
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Notes on crude oil and its by-products.

Crude Oil 5.6 Recall that crude oil is a mixture of hydrocarbons 5.7 Describe how the industrial process of fractional distillation separates crude oil into fractions Crude oil is heated, vaporised, and pumped into a fractionating column, which is coolest at the top and hottest at the bottom. The larger hydrocarbons sink whilst the smaller hydrocarbons rise up the column. As they near the area where the temperature is close to their boiling point, they condense, and the fractions are collected. The refinery gases rise straight up and are collected as gases. The longer the chain of hydrocarbons, the higher its boiling point, thus the further down the fractionating column it will be. 5.8 Recall the names and uses of the main fractions obtained from crude oil: refinery gases, gasoline, kerosene, diesel, fuel oil and bitumen Name of fraction (in order of increasing molecule size) Main uses Refinery gases Fuels for lighters and cooking Gasoline (petrol) Vehicles e.g. cars Kerosene (paraffin) Jet fuel, paraffin heaters Diesel Lorries Fuel oil Fuel for ships, factories, central heating Bitumen Roads and roofs 5.9 Describe the trend in boiling point and viscosity of the main fractions As the size of the hydrocarbon molecules increases, the boiling point and viscosity increases. This is because with increasing chain length, there are more bonds that need to be

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  • Level: GCSE
  • Subject: Science
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The Decomposition of Sodium Hydrogen Carbonate

The Decomposition of Sodium Hydrogen Carbonate Aim: the aim of this investigation is to find out the product of decomposition of Sodium Hydrogen Carbonate (NaHCO3). Hypothesis: we were given three possible products: . Sodium Oxide (Na2o) 2. (CH3CO2Na) 3. Sodium Carbonate (Na2CO3) I predict that the equations that will balance out will be considered a possible product of the reaction. The equations that will not balance out will not be considered a possible product. This is because all equations have to balance out, provided with the correct reactant and products are given. And due to this reason, the equation that will not balance will not be considered a possible product. The equations are the following: Equations of the Reaction Is it a possible Product? 2NaHCO3 --> Na2O + 2CO2 + H2O The equation balances out, and it can therefore be considered a possible product. NaHCO3 --> CH3CO2Na + CO2 + H2O The equation can not be balanced, and it can not be considered a possible product. 2NaHCO3 --> Na2CO3 + CO2 + H2O The equation balances out, and it can therefore be considered a possible product. Variables: Independent: the independent variable is the mass of crucible Dependent: the dependent variable in this experiment is the mass of residue. Controlled: . The power loss was controlled. 2. How long the mixture was heated was controlled. 3. The mass of

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  • Level: GCSE
  • Subject: Science
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Investigating the Combustion of Alcohols.

INVESTIGATING THE COMBUSTION OF ALCHOLS Planning In this investigation I will be burning alcohols to heat up a beaker of water. I will be burning five alcohols, methanol, hexanol, propanol, butanol, heptanol and pentanol. The aim is to find out how much energy is produced when burning these alcohols. 'An alcohol is a series of organic homologous compounds, with the general formula Cn H n + 1OH´. Alcohols 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. Form this reason the reactant energy is higher than that of the product. The energy is given out when forming the bonds between the new water and carbon dioxide molecules. The amount of energy produced by such exothermic reactions can be calculated by using the formula Mass of the substance x rise in temp x SHC (specific heat capacity). The specific heat capacity is the number of joules required to heat one gram of water by 1ºC. I chose to use water because it is safe, easily found, and have a reliable specific heat capacity. The bonds that are formed in an exothermic reaction can be of two types. The first could be ionic, where a metal is produced. Ionic bonding involves electrons transferring from one atom to the other consequently leaving an electrostatic force between them. The other form of bonding is covalent

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  • Level: GCSE
  • Subject: Science
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Investigating the combustion of alcohols

Investigating the combustion of alcohols Introduction: Combustion is a process of rapid oxidation of a substance with simultaneous evolution of heat and, usually, light. Alcohol is a term applied to a group of chemical compounds that contain the OH group (oxygen and hydrogen). Alcohols have one, two or three hydroxyl, -OH, groups attached to their molecules and are thus classified as monohydric, dihydric, or trihydric, respectively. Methanol and ethanol are monohydric alcohols. Alcohols are further classified as primary, secondary, or tertiary, according to whether one, two, or three other carbon atoms are bound to the carbon atom to which the hydroxyl group is bound. Alcohols are characterized by many common reactions, the most important of which is the reaction with acids to form substances called esters, which are comparative to inorganic salts. Alcohols are normal by-products of digestion and chemical processes within cells, and are found in the tissues and fluids of animals and plants. Methanol is the simplest of all alcohols. It was formerly made by the destructive distillation of wood, however, almost all methanol produced today is synthetic, made from carbon monoxide and hydrogen. Methanol is extremely poisonous and has a relative density of 0.7915 at 20°C. Ethanol is a colourless liquid with a burning taste and characteristic, agreeable odour. Ethanol is

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  • Level: GCSE
  • Subject: Science
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