Standard Enthalpy of Formation
The enthalpy change when one mole of a substance is formed from its elements in their standard states
Standard State
A substance in its most stable state at a pressure of 1 atmosphere and at a specified temperature (usually 298K)
Entropy
A measure of the degree of disorder of a system
Standard Entropy of Substance
Entropy value for the substance in its standard state
Feasible Reaction
One that tends towards the products rather than the reactants