2.1 - thermochemistry Flashcards
Define an exothermic reaction
a reaction that releases energy to its surroundings
Definition of enthalpy change
The change in the heat within a system at constant pressure
The principle of conservation of energy
Energy cannot be created or destroyed, only changed from one form to another
What are the 3 standard conditions
-Substances must be in their standard states
-Temp of 298 K
-1 atm pressure
Define the standard enthalpy change of formation
The enthalpy change when one mole of product is formed from its constituting elements, in standard states, under standard conditions.
Define enthalpy change of combustion
When one mole of a substance is combusted under standard conditions in its standard state
Equation for enthalpy change of formation
products - reactants
equation for enthalpy change of combustion
reactant - products
Hess’s Law
the total enthalpy change for the reaction is independent of the route taken for the reactants to products
Enthalpy change equation
q=mcAt
