Effect of Temperature on Solubility Lab free essay sample

What is the solubility of minerals in water? What is the relationship between temperature and solubility? Hypothesis: If salt and sugar are each tested in water of varying temperatures, then salt and sugars solubility will increase as the temperature also increases. Materials: Two 250 mL beakers Tap water 100 mL graduated cylinder Hot plate Two petri dishes Glass stirring rod Salt Sugar Thermometer Ice Balance Scoopula Graph Paper Procedure: Part 1(Tap Water) Measure 100 mL of tap water in a graduated cylinder and add the water to a 250 mL beaker. Use the balance to measure the mass of a Petri dish and record the mass in grams. Add salt to the petri dish until the mass is about 75 g. Record the mass to the nearest tenth of a gram. Use the scoopula to add a small amount of salt from the petri dish(about 5 grams) to the 250 mL of water. Stir the salt in the water with a glass stirring rod until completely dissolved, about two minutes. After the previous salt has been dissolved(no settling at the bottom of the beaker), add more bout 5 more grams of salt and repeat step number four. Continue steps 4,5,6 until saturated, no more will dissolve. Place the thermometer in the saturated solution and record the final temperature. Weigh the remaining salt in the petri dish with the balance and record. Repeat steps 1-9 with sugar instead of salt. Part 2(Cold Water) Add 100 mL of water and about six pieces of ice to a 250 mL beaker. Use the balance to measure the mass of a Petri dish and record the mass in grams. Add salt to the petri dish until the mass is about 75 g. Record the mass to the nearest tenth of a gram. Use the scoopula to add a small amount of salt from the petri dish(about 5 grams) to the 250 mL of water and ice. Stir the salt in the ice water with a glass stirring rod until completely dissolved, about two minutes. After the previous salt has been dissolved(no settling at the bottom of the beaker), add about 5 more grams of salt and repeat step number four. Continue steps 4,5,6 until saturated, no more will dissolve. Place the thermometer in the saturated solution and record the final temperature. Weigh the remaining salt in the petri dish with the balance and record. Repeat steps 1-9 with sugar instead of salt. Part 3(Hot water) Measure 100 mL of tap water in a graduated cylinder and add the water to a 250 mL beaker. Place the beaker of water on a hot plate and heat the hot it until the temperature reads 90Â °C. Turn the hot plate off. Use the balance to measure the mass of a Petri dish and record the mass in grams. Add salt to the petri dish until the mass is about 75 g. Record the mass to the nearest tenth of a gram. Use the scoopula to add a small amount of salt from the petri dish(about 5 grams) to the 250 mL of hot water. Stir the salt in the water with a glass stirring rod until completely dissolved, about two minutes. After the previous salt has been dissolved(no settling at the bottom of the beaker), add more about 5 more grams of salt and repeat step number four. Continue steps 4,5,6 until saturated, no more will dissolve. Place the thermometer in the saturated solution and record the final temperature. Weigh the emaining salt in the petri dish with the balance and record. Once dissolved, five more grams were added and the process repeated until no more salt or sugar could be dissolved. When this point was reached, the solution was pronounced saturated. A final temperature of the saturated solution was recorded in Celsius. The remaining salt or sugar in the petri dish was weighed. The final mass of the Petri dish and mineral was subtracted from the initial mass of the Petri dish and mineral. This number was the amount of dissolved salt in the water. In this experiment the independent variable was the temperature and the dependent was the solubility. The controls included the brand and type of each mineral, the source of the water that was used, and the units for measuring temperature and solubility. The lab was performed to test the effect that temperature has on solubility. The hypothesis If salt and sugar are each tested in water of varying temperatures, then salt and sugars solubility will increase as the temperature also increases was supported by most of the data. Sugar showed the trend that with an increased temperature, the solubility increases. Tap water at 19Â °C had a solubility of 35 g/100mL of H2O, which is 10 grams higher than the solubility of sugar at 10Â °C. Also, tap water at 16Â °C dissolved 16 g/100mL of salt which is less than the amount dissolved at 74Â °C. An unidentified error occurred during the test of the effect of cold water on the solubility of salt. The solubility should have decreased and been less than that of the tap water and hot water. The results exhibited here show that though the temperature is 11 degrees lower than that of tap water, the solubility is 9 g/100 mL higher. The error possibly could have occurred in the weighing of the final amount of salt or the calculations. Had the error not occurred, the hypothesis would have been completely supported by the data. In general, the higher the temperature of a solvent, the more of a given solid solute it can dissolve. The solvent in this experiment was water, and the solid solutes were sugar and salt. Based off of the data with errors that was collected, it can be assumed that to dissolve 25 grams of salt one would need water at 5Â °C. More likely though, 25 grams of salt dissolves at at a temperature between 16Â °C and 74Â °C. From the graph created, one can assume that if the trend is followed approximately 65 g/100mL would dissolve at 50Â °C. This prediction is based of the fact that for every 10Â °C increase, the solubility also increases by about 10 g/100mL. Conclusion: In conclusion, the hypothesis that If salt and sugar are each tested in water of varying temperatures, then salt and sugars solubility will increase as the temperature also increases is supported by most of the data obtained.