A 3.96 g sample of carbon is introduced into the combustion chamber of a calorimeter containing 500.0 g of water. The carbon sample is burned completely to form carbon dioxide gas, and the surrounding water temperature increases from 20.0oC to 82.0oC. The heat capacity of the calorimeter is 1.8 J/oC. A. Calculate the total amount of heat released inside the calorimeter in kJ. B. Determine the heat of combustion of carbon in kJ/mole of carbon. C. Does your answer in b make sense given that the enthalpy of formation of CO2= ΔHrxn = -393.5 kJ/mole?
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.
A 3.96 g sample of carbon is introduced into the combustion chamber of a calorimeter containing 500.0 g of water. The carbon sample is burned completely to form carbon dioxide gas, and the surrounding water temperature increases from 20.0oC to 82.0oC. The heat capacity of the calorimeter is 1.8 J/oC.
A. Calculate the total amount of heat released inside the calorimeter in kJ.
B. Determine the heat of combustion of carbon in kJ/mole of carbon.
C. Does your answer in b make sense given that the enthalpy of formation of CO2= ΔHrxn = -393.5 kJ/mole?
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