The decomposition of one mole of hydrogen peroxide, H2O2(s), into water and oxygen gas, at constant pressure releases 98 kJ of heat. Write a balanced thermochemical equation for the reaction. Which has the higher enthalpy under these conditions, the reactants or the products? How many kJ of energy would be released if 68 grams of hydrogen peroxide are decomposed.
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.
The decomposition of one mole of hydrogen peroxide, H2O2(s), into water and oxygen gas, at constant pressure releases 98 kJ of heat.
- Write a balanced thermochemical equation for the reaction.
- Which has the higher enthalpy under these conditions, the reactants or the products?
- How many kJ of energy would be released if 68 grams of hydrogen peroxide are decomposed.
- Would the enthalpy change for the reaction be greater or less if water vapor formed rather than liquid water?
- Write a balanced thermochemical equation for the reverse of the reaction you wrote in (a) above.
- For the reaction in (e) how many kJ of energy would be required to make 17 grams of hydrogen peroxide?
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
