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Designing a Hand Warmer. http://group.chem.iastate.edu/Greenbowe/sections/projectfolder/flashfiles/thermochem/solutionSalt.html.
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http://group.chem.iastate.edu/Greenbowe/sections/projectfolder/flashfiles/thermochem/solutionSalt.htmlhttp://group.chem.iastate.edu/Greenbowe/sections/projectfolder/flashfiles/thermochem/solutionSalt.html Breaking bonds and particulate attractions absorb E from the surroundings, while forming new bonds and particulate attractions release energy to the surroundings. When an ionic solid dissolves in water, ionic bonds between + and – ions and H bond b/t water molecules are broken, and NEW attractions between water/anions and cations are formed. The E required to break these bonds and form new ones depends on the properties of the anions and cations. Heat evolved, q = -, exothermic Heat absorbed, q = + and endothermic ENTROPY of solution is ALWAYS (+)
Pre-Lab Part A: • Heat Capacity of the Calorimeter Part B: • Practice Calorimetry Procedure with MgSO4(s)
In groups, review the calorimetry procedure and answer the following questions:
Each group will use 3 solids (we will share data at the end) Group A: • ammonium nitrate • Calcium chloride • Sodium acetate Group B: • Sodium chloride • Lithium chloride • Sodium carbonate