10.6 Hess’s law and standard enthalpies of reaction Flashcards
1
Q
Hess’a Law
A
the principle that the enthalpy of a reaction for a process that is the sum of two or more reactions is equal to the sum of the delta H rxn values of the constituent reactions: also called Hess’s law of constant heat of summation
2
Q
standard enthalpy of reaction
A
the enthalpy change associated with a reaction that takes place under standard conditions also called the standard heat of reaction
3
Q
standard conditions
A
in thermodynamics: a pressure of 1 bar (1 atm) and some specified temperatures assumed to be 25 degrees celsius unless otherwise stated; for solutions a concentration of 1 M is specified
4
Q
standard state
A
the most stable form of a substance under a pressure of 1 bar and some specified temperature usually 25 degrees celsius
