KBr dissociates in water according to the following equations: KBr(s) --> K+(aq) +Br-(aq) a) 10.5g of KBr are dissolved in 125g of water in a calorimeter and you observe the temperature of the water decrease from 24.2 to 21.10 Celsius. What is the enthalpy of the solution of KBr in kj/mol? Heat capacity of solution is 4.184 J/gC. Molar mass of KBr is 119.0g/mol. b) Explain why the dissolving of KBr in the water is endothermic OR exothermic reaction? Explain. c) If you dissolved 24.0g of KBr in water, would you expect the temperature of the water to increase or decrease? Explain.
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.
KBr dissociates in water according to the following equations:
KBr(s) --> K+(aq) +Br-(aq)
a) 10.5g of KBr are dissolved in 125g of water in a calorimeter and you observe the temperature of the water decrease from 24.2 to 21.10 Celsius. What is the enthalpy of the solution of KBr in kj/mol? Heat capacity of solution is 4.184 J/gC. Molar mass of KBr is 119.0g/mol.
b) Explain why the dissolving of KBr in the water is endothermic OR exothermic reaction? Explain.
c) If you dissolved 24.0g of KBr in water, would you expect the temperature of the water to increase or decrease? Explain.
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