Heat of Solidification Lab-Writeup

Introduction In chemistry, fondnesss require a certain meat of muscle in the form of average kinetic energy (temperature) to freeze. To reach the temperature a substance requires to freeze, it essential lose a certain amount of wake energy (a form of energy transferred from one object to another, because of a temperature difference). When a substance reaches its freezing point and begins to freeze, its temperature remains unending until it is completely frozen.However, in purchase order to melt a substance essential go done a energy motley, creating the problem, What energy changes occur when a liquid solidifies? . To mold the problem, a hypothesis was proposed, stating When a substance begins to solidify, it releases high temperature energy, because a substance must reach its disturb of solidification ( cacoethes required to freeze) by losing a certain amount of heat, in order to solidify. In order to test this hypothesis, a experiment was performed. Materials and Metho dsIn the experiment, the materials required were 1 get on shake off in a test electron tobacco pipe with the weight of the test tube labeled, a 250 mL beaker, a ringstand, a wire gauze, a gradational cylinder, a Bunsen Burner, a styrofoam calorimeter, and a thermometer. To perform the experiment, first the calorimeter was change with 100 mL of water supply system exploitation a graduated cylinder, and the temperature of the water was found and recorded. Next, the beaker was filled 3/4 full with water and dictated on the stand of the ringstand above a gently burning burst out from the Bunsen Burner.Then, the mass of the test tube and ride was found and recorded, and the tube was placed in the beaker. afterward the grow in the tube melted, the tube was placed in the calorimeter, using a wire gauze. Lastly, once the wax in the tube solidified, the temperature of the water in the calorimeter was measured and recorded. Results Data preserve During Experiment Mass wax and t est tube41. 2 gramsTemperature water later heating26 ? C Mass give up test tube21. 0 gramsTemperature water before heating16 ? C Mass wax20. 2 gramsTemperature change10 ? CVolume water used100 mLMass of water used100 grams In the info table above, the mass of the wax was found by subtracting the mass of the empty test tube from the mass of the wax and test tube, bragging(a) an perform of 20. 2 g. To find the flock of water used, the mass of the water was figure by the density of the water, giving an answer of 100 g. To find the temperature change of the water, the temperature of the water after heating was subtracted by the temperature of the water before heating, giving an answer of 10 ? C. CalculationsAfter the experiment, the heat gained by the water from the wax in the calorimeter was calculated using the face q = mC? T, where C equaled 4. 18 J/g * ? C. After the corresponding ranges were plugged in, the equation 100g(4. 18 J/g * ? C. )(26? C-16? C) was created and so lved for an answer of 4180 J of heat gained. After the amount of heat gained was found, the heat released per gram of wax (heat of solidification) was calculated using the equation 4180 J/20. 2g, giving an answer of 206. 93 J released per gram of wax.Although the heat released per gram of wax, found through the calculations, was 206. 93 J, the accepted value was 150. 0 J/g, because of this, the percent fallacy was calculated using the formula(measured actualactual)100. After the values were plugged in, giving the equation(206. 93 J/g 150. 0 J/g150. 0 J/g)100, the percent error was found to be 38%. Discussion After the results were found, a terminal was drawn up supporting the hypothesis. In the experiment, the temperature of the water increased from 16 ? C to 26 ? C after the wax solidified.This showed that the wax must have released heat energy, in order to cause the temperature of the water to change, due(p) to temperature requiring heat to change. In a experiment, there are many diametrical possible descents of scientific error. In the experiment that was preformed, two possible sources of error were determined. The first source of error found was, the thermometer may have miss-measured the temperature of the water after the wax solidified, too high or low, which would have caused the heat of solidification to be too high or low.The other source of error was the wax may not have fully solidified, which would have made the heat of solidification too low, due to the wax not fully releasing its heat energy. To better understand the experiment that was preformed, summer-flowering questions were asked. The first question asked was, The heat of burning of wax is 45,000 J/g. explain why there is such a large difference amid the heat of solidification and heat of combustion in terms of the typecast of change.To answer the question, a answer was made Due to the heat of combustion of wax being the heat released from the chemical reaction betwixt oxygen and wax, it is a chemical change and because the heat of solidification of wax is a physical change and chemical changes release a significantly larger amount of heat then physical changes, the heat of combustion of wax releases a much larger amount of heat. The back up question asked was The amount of heat released by the solidifying was is equal in magnitude to the amount of heat that the wax inattentive when it melted.Explain why this is so in terms of the arrangement of molecules in liquids vs. solids. To respond to this question the response In order to change the arrangement of molecules from a solid to a liquid state, the wax must absorb a certain amount of heat and in order to return to a solid state, it must release the energy it absorbed. In the last question, the following was asked Predict the achievement of the change in the mass of the wax used or volume of water in the calorimeter on the following parameters.Assume all variables remain constant other then the one listed. If twice the amount of wax or half the amount of water was used in the experiment, how would the temperature, heat absorbed by the water and the calculated heat of solidification change. Explain your predictions for the heat of solidification. In the answer responding to the question, it was stated, both the temperature and heat absorbed by the water would increase, however the heat of solidification would stay the same, due to the wax continuing to release the same amount of heat per gram of wax.