Energetics Flashcards
What is an endothermic reaction
One with an overall positive enthalpy change
Energy in breaking bonds > energy out making bonds
What is an exothermic reaction
One with an overall negative enthalpy change
Energy in breaking bonds < energy out making bonds
Define standard enthalpy of formation
The enthalpy change when one mole of a compound is formed from it constituent elements in standard conditions with reactants and products in their standard states
Standard enthalpy of combustion
The enthalpy change when one mole of a substance is burnt completely in oxygen in standard conditions with reactants and products in their standard states
How can you calculate enthalpy change from experimental data
Q = mc()T
What is hess’ law
States that the enthalpy change for a reaction is the same regardless of the route taken
What is the enthalpy of an element
The enthalpy of all elements in their standard states
Define bond dissociation enthalpy
The enthalpy charge required to break a covalent, with all species in the gaseous state
Define mean bond enthalpy
Average values for the bond dissociation enthalpy of a given bond
