In the following experiment, a coffee-cup calorimeter containing 100 g of H20 is used. The initial temperature of the calorimeter is 23.0 °C. If 4 g of CaClzis added to the calorimeter, what will be the final temperature of the solution in the calorimeter? Assume that the heat capacity of the solution is 4.18 J/g°C, and that the heat capacity of the calorimeter is negligible. The heat of dissolution AHsoln of CaCl2 is -82.8 kJ/mol. Enter your answer numerically in terms of °C.
Thermochemistry
Thermochemistry can be considered as a branch of thermodynamics that deals with the connections between warmth, work, and various types of energy, formed because of different synthetic and actual cycles. Thermochemistry describes the energy changes that occur as a result of reactions or chemical changes in a substance.
Exergonic Reaction
The term exergonic is derived from the Greek word in which ‘ergon’ means work and exergonic means ‘work outside’. Exergonic reactions releases work energy. Exergonic reactions are different from exothermic reactions, the one that releases only heat energy during the course of the reaction. So, exothermic reaction is one type of exergonic reaction. Exergonic reaction releases work energy in different forms like heat, light or sound. For example, a glow stick releases light making that an exergonic reaction and not an exothermic reaction since no heat is released. Even endothermic reactions at very high temperature are exergonic.
Determination of heat released by dissolution of as;
Heat released by dissolution =
Now, the amount of heat released by the dissolution of will be equal to amount of heat absorbed by water.
Now, determine the amount of temperature change as;
Where, m is the mass, C is specific heat, is temperature change and Q is heat.
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