Thermochemistry: Endothermic And Enthalpy

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The term Thermochemistry refers to when heat is evolved or absorbed during a chemical reaction. When calculating the amount of energy, the number will always be expressed as a positive number. A negative sign will indicate whether the energy is evolved or absorbed. If the sign is negative, then the energy is evolved and if the sign is positive, then the energy is absorbed. The amount of heat that is released or absorbed will also be in units of Joules or Kilojoules per mol. There are two other terms to be familiar with, which are endothermic and exothermic. Endothermic is another way of referring to the absorption of energy and exothermic is the release of energy. For this experiment, you will be using a calorimeter. What is a calorimeter? A calorimeter is a device used to measure the amount of heat that is involved in a chemical reaction. This is the device we will be using to determine the amount of heat produced by a chemical process. Another term to know is Enthalpy, as stated in the lab website glossary, Enthalpy, “is the sum of the internal energy of a system and the product of its pressure and volume.”
Experimental Procedures: For this experiment there are two parts that need to be completed followed by, Lab Clean-up. The reagents used in part 1 of this experiment are NaOH,
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For this part you will be “studying heat reaction values with Hess’s Law. In part 2A you will repeat the same experiment you did in part one and calculate the heat reaction. Part 2B you will conduct the same experiment, but this time you will be adding a solid NaOH reagent, as well as in part 2C, but without the presents of HCI. The last part you are trying to determine whether or not there would be an “observable difference” if you conducted the same reaction in part 2A, but used a different acid (CH3COOH.) Once you have conducted all of these parts, you will clean up everything and put the equipment back where it

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