To find out what fuel releases the most heat energy whereas the amount of fuel wasted is also accounted for; we could test a number of well-known fuels (provided by the school) and contemplate their bonding attributes and components which they are composed of (all fuels are compounds, so they are made up of number of hydrocarbons, thus bonds are customary during combustions The main emphasis of this experiment is to identify not only the energy potential emitted by the fuels in a given amount of time, but also to discover how and most importantly why every fuel releases the amount of energy that correspondingly.
Of course in order to accomplish this test fairly, time, fire intensity, water (substance) levels Will be considered once implemented into the equation. Variables: Independent Variable * The different fuels used in the experiment. Dependent Variable The combusted energy taken in by the body of water (LA in Kilo Joules). Controlled: Amount of water used for heating (1 ml). * Calorie Meter. Starting temperature of water inside boiling tube (ICC). Amount of time boiling tubes are heated (2 minutes). The placement and size tot the hole (in the foil covering the calorie meters cap) where the thermometer was put through. * Weighing scale (ml).
Hypothesis: Similar to enthalpy but differs in terms of the output capacities which are even in Kilojoules and interpreted into moles, and the formulas utilized to discover the energy yield of combustion. Our group investigated the difference in enthalpy changes for the combustion of different alcohols. This is done to find out how the number Of carbon atoms a fuel contains effects the enthalpy change during complete combustion. To do this we ignited the combustible thread-lid Which links directly to the fuel and arrange for as much Of the energy as practically possible to be transferred to the water through energy heating.
In theory, the more hydrocarbons that a fuel has, the more energy that is going to e produced QUICK-RECAP: A Hydrocarbon is a compound of hydrogen and carbon, such as any of those that are the chief components of petroleum and natural gas. To work out the enthalpy change of combustion for the alcohols we use the assumption that LLC of water is equal to lag. Using this assumption we then use the equation energy absorbed MS;-AT; which means Amount of energy mass of water x specific heat capacity x temperature rise.
Instead, we also use the preferable scientific formula [K – mica) to find the potential energy absorption in the waters temperature, being the Kilojoules (output), ‘m’ being mass of he water, and the remaining is the specific heat capacity times the temperature rise, respectively. Obviously, as the equation suggests, all these values in the other side of the equation (right side where the components are i. E. mica) are multiplied together. Because it is a controlled variable, the waters mass and volume will be preserved throughout the experiment, not to mention its own mass of 0. KGB (log). The specific heat capacity is 4. 2. Something to pay attention to is the change in temperature in all objects utilized in the test, Obviously heat energy is rendered from one medium to another, and how much of it solely depends on the molecular Structure (so the item(s) could be either a insulator or conductor): So to establish and maintain the original equilibrium of objects (how high the temperature was per item at the beginning Of the test) we had to cool down all tools and including the thermometer.
Thankfully, the thermometer granted us the privilege to be able to measure the temperature of all necessary objects (the water for example had to be settled to the room temperature of the room). By the time all was set, the next trial could initiate. This entire procedure enables us control the variables of the experiment, Some of the elemental combustibles prone to fire are hydrocarbons, because they contain carbon and hydrogen, and fire thrives on oxygen, carbon and hydrogen in this scenario. So it is very expected that whatever combustible holds the most hydrocarbons will be the most flammable and energetic.
Another way to describe how this works is by the emphasis tot how toot gives energy to the consumer: some toots nourish us more than others depending on the kilojoules that they have. Carbohydrates are often high on kilojoules and calories, which is precisely why they are essential for exercising routines. How does this relate to the context? Well, we can relate the carbohydrates to the fuels and the outlay of energy by the body to the exothermic reaction given off by the ignition of the fuel How much is given off really depends on the amount of kilojoules, and this applies to both situations.
To calculate the change between the fuels we must work out the Enthalpy change of combustion when 1 mole of a fuel is burned thoroughly under normal conditions in room temperature. Calculate the number of moles burned per fuel by finding each of the fuel’s molecular mass and then applying their respective ATA into the equation. Apparatus: 1. Clamp Stand 2. Match Sticks Box 3. Stopwatch jell$’;; 4. Fuels – varying) 5. Calorie Meter 6. Thermometer 7. Water (Mimi -XII) 8. Measuring cylinders (1 Mol) 9. Aluminum Foil Sheet(s) 10. Safety goggles 11.
Metal Water cup/mug Method(s): l. Trial commencement: Collect equipment and apparatus (remember to apply safety precautions! ). 2. Set up the clamp stand, adjust the claw in a way it would be able to wrap around the cup and have a satisfactory grip on it so it does not collapse. 3. Once the cup is lodged into the Clamp, conceal the lid of the up with a piece of aluminum fabric, and then proceed to puncture the region where the hollow gap in the lid was. 4. Measure the mass of the fuel, and the container in which it is held (without the fuel). . Pill the measuring cylinder with roughly 10 millimeters of water, and then unload the contents into the cup/ mug in the clamp 6. Set up the Bunsen burner below the cup’s lower surface; attach the cord into the gas compartment. 7. Place a thermometer through the aluminum gap so the thermometer can contact the water. Measure the temperature of the water, the distilled water should have room temperature. 8. Ignite a matchstick and switch the gas on make the Bunsen burner catch fire and create a flame. 9.
Pentane-l -01 has the greatest number tot carbon atoms in the chain and also the highest enthalpy change of combustion. Therefore as the number of carbon atoms increases the enthalpy change also increases. This is because as he number of carbon atoms in a chain increases the number of bonds which can be broken also increases. Bond breaking is endothermic which means energy is given out to the surroundings. The more carbon atoms there are in a chain the more energy there will be given out to the surroundings through the breaking of bonds, therefore the greater the enthalpy change of combustion.
Methanol has the least number of carbon atoms, therefore the least number of bonds broken which results in lower enthalpy change of combustion as less energy is given out to the surroundings. Pentane-l-lo has the greatest number of carbon atoms in the Hahn, therefore the most number Of bonds broken Which results in the highest enthalpy change of combustion as more energy is given out to the surroundings. The alcohols increase in size by a CHI group each time. This results in an increase of approximately KICK] mole for the enthalpy change of combustion.
This increase is attributed to the fact there is 1 more C. C bond and 2 more CHI bonds broken each time, which means the burning of the fuel is more exothermic so more heat will be given out to the surroundings and the enthalpy change will be greater. The bonds are broken and new bonds are formed to give the products eater and carbon dioxide. As the alcohols increase in size by a CHI group 1 more water and 1 more carbon dioxide are produced. As you can see from the results table my results are much smaller than the data book values, possible explanations will be given for this in the Evaluation.
Evaluation: The results showed to be quite off what was expected: some trial data differed from one another dramatically. Due to the heat energy loss many of the energy was lost through the exothermic reactions, in which some of the heat is transferred from one medium into other surrounding mediums such as the air. It s inevitable that during this investigation numerous errors will occur; human error can be a factor the heat from the cup/mug could have been transferred to the clamp, the tap water could have different cooling levels than other waves.
Some will be procedural errors others will be due to human error. These errors have reduced the accuracy of my results. Firstly human error may have occurred when taking readings and measurements, this is inevitable and little Can be done to prevent it. But that does not imply that the conclusion of the experiment was wrong, we still managed to come in terms With a valid solution and thesis, most importantly, the hypothesis we had originally alleged was relatively precise. Bibliography: 1. R, Nave. Hydrocarbons.