Full Lab Manual
Introduction & Goals
Chemistry & Background
In Your Write-up
Your goal for this week is to identify chemical compounds which could be used to produce a chemical "cold pack" and a chemical "hot pack" to treat sports injuries. In this experiment you will determine the heats of reaction for an exothermic and an endothermic reaction in solution and learn what factors contribute to the spontaneity of the two reactions under study.
To Learn or Review
Heat, Heat Capacity, and Calorimetry
Zumdahl, pp. 345-350, 360-363
Enthalpy and Hess's Law
Zumdahl, pp. 351-352, 357-370
Gibbs Free Energy and Spontaneity
Zumdahl, pp. 418-421
In last week's experiment, you used a solution calorimeter to determine the heats of reaction for several different reactions and then calculated the heat of formation for MgO using Hess's Law. This week you will use solution calorimetry to investigate the thermodynamic properties of a variety of ionic compounds, or salts, as they dissolve in water. You and your partner will choose one ionic compound that will be potentially useful as a chemical hot pack and one that may be useful as a chemical cold pack. You will determine the enthalpy change when each salt dissolves and compare to the literature values. You will see how the enthalpy contributes to the spontaneity of each reaction.
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