Energetics Flashcards
What is delta H?
is the heat energy change at constant pressure and under standard conditions of 298k, 100KPa and 1 mole.
What is bond dissociation energy?
The enthalpy (heat energy) change when 1 mole of a particular covalent bond is broken, all species are in the gaseous state. Under standard conditions of 298K, 100KPa and 1 mole.
What enthalpy is this?
Cl2 (g) —-> 2 Cl (g)
What is average bond energy?
The average or mean enthalpy change when 1 mole of a particular covalent bond is broken, when averaged over many different environments, all species in the gaseous state.
What enthalpy is this?
CH4 —–> C(g) + 4H(g)
What is the enthalpy of formation?
The enthalpy change (heat energy) when 1 mole of a compound is formed from its elements, all reactants and products in their standard states when measured under standard conditions of 298K, 100KPa and I mole.
What enthalpy is this?
1/2H2 + 1/2N2 + 1 1/2O2 —–> 1HNO3
What is the enthalpy of combustion?
The enthalpy (heat energy) change when 1 mole of a substance is burnt in excess oxygen, all reactants and products in their standard conditions of 298K and 100KPa.
What does Hess’ Law state?
The enthalpy change at constant pressure is independent of the route. The initial and final energy states are constant.
