Background and Prediction Essay Example

Background and Prediction Essay Example Background and Prediction Essay Background and Prediction Essay Evaporation is the process of a substance turning from its liquid form to its gaseous form. This occurs when a substance (in liquid form) is heated to a certain temperature this temperature varies between substances and is called the boiling point. What happens is that as heat is applied to the liquid the particles inside it absorb the energy from the heat and become more and more excited (they vibrate more quickly) as more heat is applied. Eventually the particles become so excited that they break free from the surface of the liquid and become vapour. Evaporation has occurred at this point.The reason a liquid becomes a gas when the particles become excited is that a gas has much weaker inter-molecular bonds than a liquid. A solid has the strongest inter-molecular bonds so that is the most difficult state of substance to manipulate.Things which could affect the speed of evaporation are:* Type of liquid;* Colour of liquid;* Colour of container;* Aperture of container.I am going to in vestigate how the type of liquid affects the speed of evaporation. I will create an experiment in order to find out.The ExperimentPlanI will pour 20cmà ¯Ã‚ ¿Ã‚ ½ of three different substances (ethanol, water and paraffin) into separate beakers. I will then place the three beakers into an incubator at 60à ¯Ã‚ ¿Ã‚ ½C for 30 minutes. After 30 minutes I will remove the beakers from the incubator and pour out the liquid from each beaker into its own measuring cylinder in order to find out how much of each substance evaporated.EquipmentI will need:* Incubator;* Stopwatch;* Thermometer;* 3 measuring cylinders* 3 beakers;* Ethanol;* Paraffin;* Water.PredictionI predict that the water will evaporate the most because it has the lowest atomic mass (18) of the three substances. Paraffin will hardly evaporate, if at all, due to its huge atomic mass (632!).ResultsWaterEthanolParaffinBefore20cmà ¯Ã‚ ¿Ã‚ ½20cmà ¯Ã‚ ¿Ã‚ ½20cmà ¯Ã‚ ¿Ã‚ ½After18cmà ¯Ã‚ ¿Ã‚ ½10cmà ¯Ã‚ ¿Ã‚ ½20cmà ¯Ã‚ ¿Ã‚ ½The da ta that I have collected may be inaccurate because while the beakers were in the incubator somebody tampered with the temperature control. However, there was not enough time for me to repeat the experiment and recollect all of the data so I am continuing with the data I already have. An improvement to the accuracy of the experiment would be to weigh the beakers of liquid before and after placing them in the incubator as no droplets would be lost transferring liquid between beakers.AnalysisThe results of this experiment show that ethanol evaporated the most with just 10cmà ¯Ã‚ ¿Ã‚ ½ remaining after being in the incubator for 30 minutes. The water didnt evaporate as much as I expected with 18cmà ¯Ã‚ ¿Ã‚ ½ left after 30 minutes. Paraffin did not evaporate at all after 30 minutes there was still 20cmà ¯Ã‚ ¿Ã‚ ½ left in the beaker.These results partly support my prediction and partly contradict it. They support it in that as I predicted, paraffin did not evaporate at all. However, th ey contradict it in that ethanol evaporated much more than water did. I have no idea why this happened because water had a lower atomic mass than ethanol.EvaluationThe only part of my results which I expected was that of paraffin not evaporating. The results for ethanol and water surprised me as the substance with the lower atomic mass (water) did not evaporate nearly as much as the substance with the higher atomic mass (ethanol).The experiment could be improved for greater accuracy by weighing the beakers of liquid before and after they are placed into the pre-heated incubator for a set amount of time. This would prevent loss of water when transferring substances between containers.To be entirely satisfied with my data I would need to do this experiment at least three times to ensure that I had collected accurate data. I would also ensure that the actual liquid was at 60à ¯Ã‚ ¿Ã‚ ½C for 30 minutes rather than the environment into which the liquid was placed being at 60à ¯Ã‚ ¿Ã‚ ½ C for 30 minutes.