chapter 9 and 10 enthalpy and reaction rates and equilibrium

catalyst

a substance that increases the rate of a chemical reaction without undergoing any permanent change itself

homogeneous catalyst

same physical state as reactants

heterogeneous

different physical state from reactant

enthalpy

a measure of heat energy present in a chemical system

enthalpy change

the amount if energy released or taken in during a chemical reaction

conservation of energy

energy cannot be created or destroyed

exothermic

a reaction which releases energy into the surroundings

endothermic

a reaction which takes in energy from the surroundings

activation energy

the minimum energy required for a reaction to take place

standard enthalpy change of formation

the enthalpy change associated with the formation of one mole of compound from its elements under standard conditions

standard enthalpy change of reaction

the enthalpy change associated with a stated equation in the molar quantities shown in the chemical equation under standard conditions

standard enthalpy change of neutralization

the enthalpy change associated with the formation of one mole of water from a neutralization reaction between an acid and a base under standard conditions

standard enthalpy change of combustion

the enthalpy change associated with the complete combustion of one mole of substance under standard conditions

Hess’ law

if a reaction can take place by two routes and the starting and finishing conditions are the same the total enthalpy change is the same for each route

average bond enthalpy

the energy required to break one mole of a specified type of bond in a gaseous molecule