Introduction:
Hot packs work by dissolving a salt, such as calcium chloride, in water to create an exothermic reaction. When salts are dissolved in water it requires energy to break their bonds apart, but energy is also released when the ions are surrounded by the water molecules. If more energy is released than is required to break the bonds, the reaction will be exothermic and will produce heat. In hot packs the water is kept separate from the salt, and when it needs to be activated, they are combined by breaking an inner membrane. If the salt was already mixed in with the water before it was needed, it would activate the reaction too early, thus rendering it useless. The purpose of this lab was to determine the quantity of calcium chloride required to create a hot pack that increased temperature by 55 o C. …show more content…
The data supports this conclusion because the trend of the data (line of best fit) shows that with 26.6 g of calcium chloride, the change of temperature will be exactly 55 o C. There may have been some limitations to the data in this lab. When measuring temperature, stirring of the thermometer had a big effect. The stirring, however, wasn't very consistent throughout all three trials which may have caused inaccuracies. The equipment may have also been a limitation in this lab. The scale used to measure the calcium chloride only went to tenths of a gram which could have made the masses inaccurate. Also the thermometer used only measured to single degrees and may not have been as accurate as a digital one. One thing that could be changed for next time would be more testing of different masses of calcium chloride, because three trials wasn’t enough to be accurate. Another change for next time could be the use of a polynomial line of best fit to calculate the desired temperature, as a linear line isn’t well suited for this
Hot packs work by dissolving a salt, such as calcium chloride, in water to create an exothermic reaction. When salts are dissolved in water it requires energy to break their bonds apart, but energy is also released when the ions are surrounded by the water molecules. If more energy is released than is required to break the bonds, the reaction will be exothermic and will produce heat. In hot packs the water is kept separate from the salt, and when it needs to be activated, they are combined by breaking an inner membrane. If the salt was already mixed in with the water before it was needed, it would activate the reaction too early, thus rendering it useless. The purpose of this lab was to determine the quantity of calcium chloride required to create a hot pack that increased temperature by 55 o C. …show more content…
The data supports this conclusion because the trend of the data (line of best fit) shows that with 26.6 g of calcium chloride, the change of temperature will be exactly 55 o C. There may have been some limitations to the data in this lab. When measuring temperature, stirring of the thermometer had a big effect. The stirring, however, wasn't very consistent throughout all three trials which may have caused inaccuracies. The equipment may have also been a limitation in this lab. The scale used to measure the calcium chloride only went to tenths of a gram which could have made the masses inaccurate. Also the thermometer used only measured to single degrees and may not have been as accurate as a digital one. One thing that could be changed for next time would be more testing of different masses of calcium chloride, because three trials wasn’t enough to be accurate. Another change for next time could be the use of a polynomial line of best fit to calculate the desired temperature, as a linear line isn’t well suited for this