120. Consider the following reaction at 248°C and 1.00 atm: CH;Cl(g) + H2(g) → CH.(g) + HCI(g) For this reaction, the enthalpy change at 248°C is -83.3 kJ/mol. At constant pressure the molar heat capacities (C,) for the compounds are as follows: CH;CI (48.5 J K-1 mol-1), H2 (28.9 J K-1 mol-1), CH4 (41.3 J K-1 mol-1), and HCl (29.1 J K-1 mol-1). a. Assuming that the C, values are independent of -bnuo temperature, calculate AH° for this reaction at 25°C. lo da b. Calculate AH? for CH;Cl using data from Appendix 4 and the result from part a.
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.
appendix 4 provides the information
deltaH H2 =0kJ/mol
deltaH CH4 =-75kJ/mol
delta HCl =-92kJ/mol
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 3 images
