I am struggling very much with this calculation and would like a well explained way to find the solution, thank you. When 0.0129 mol of KI are dissolved to 40.0 g of solution, the temperature of solution decreased by 1.57 °C. Assuming the container did not absorb or lose any heat, and the solution has Cp = 4.184 J/g °C, what is the ΔH° for the reaction: KI(s) → K+(aq) + I¯(aq)
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.
I am struggling very much with this calculation and would like a well explained way to find the solution, thank you.
When 0.0129 mol of KI are dissolved to 40.0 g of solution, the temperature of solution decreased by 1.57 °C. Assuming the container did not absorb or lose any heat, and the solution has Cp = 4.184 J/g °C, what is the ΔH° for the reaction:
KI(s) → K+(aq) + I¯(aq)
ΔH° = (m×Cp ×Δt)/n -----(1)
Where m is mass of solution
Cp is heat capacity
Δt is change in temperature
n is number of moles of solute
Given data:
Δt=1.57 °C
Cp = 4.184 J/g °C
m = 40.0 g
n = 0.0129mol
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