Enthalpy and Bond Strength

Vocabulary

bond enthalpy

energy needed to break a bond in 1 mole of a gaseous substance

Born-Haber cycle

method to calculate the enthalpy of formation of a lattice structure

enthalpy (H)

internal energy of a system plus the work needed to displace the environment to produce the components of the system

Hess's law

law that states that in a multistep reaction, the reaction enthalpy is equal to the sum of the reaction enthalpies for each individual step

internal energy (U)

sum of all kinetic energy and potential energy of the particles in a system

lattice energy

energy needed to form a lattice structure (which always has a negative value)

standard state

set of specific conditions under which reactions are measured, typically 0°C and 1 atm pressure

system

part of the universe that is under consideration

work (w)

energy that is transferred when a force acts on an object over a distance