Cold Pack Essay

INTRODUCTION Using the correct type of medical product to treat an injury is crucial for the injury to heal. A common product used in treatment of injury is a cold pack. After injury, it is common practice to ice the affected area to reduce swelling and therefore soothe the area. There are many types of cold packs that can be used, the most common being ice in a bag of sorts. Another popular kind of ice pack is disposable that consists of a small, thin compartment that contains a salt (NH4NO3) inside a larger, thicker compartment that contains water. When the small compartment is broken open, the salt goes into the water and dissolves, which results in temperature change around 15°C. Three process happen at the same time to account for the
Enthalpy is the change in heat which, in the case of a cold pack, is endothermic. It is endothermic because the system is absorbing heat. The heat given off by the solution, or ΔHsoln, can be found by adding the changes in the enthalpy in each step together. In the case of the cold pack, the enthalpy of the solution after it is broken can be found by using the equation:
ΔHsoln = ΔHsolute + Δhydr
Where ΔHhydr is the heat of the water, and the ΔHsolute is the heat of the salt (NH4NO3). In this experiment, a device that measures heat, a calorimeter, will be used. For this experiment, a calorimeter will be made with two nested Styrofoam cups, cardboard to cover the top as a lid, a thermometer, as well as about 25mL of water and about 7g of NH4¬NO3. The temperature of the solution will be closely monitored with the thermometer. The heat that is absorbed (qsoln) should be equal but the opposite sign to the heat lost by the calorimeter (qcal¬), which is shown in the equation qsoln = qcal Finally, the heat change for the calorimeter (qcal) will equal the measure temperature change (ΔT) times the heat capacity of the calorimeter using the