Thermodynamics - L3 Enthalpy

H Gen Chem 1

enthalpy

the state function that keeps track of losses of energy as expansion work during heat transfer at a constant pressure

enthalpy letter

H

U, P, and V are all

state functions

at a constant pressure and no nonexpansion work

deltaH=q

enthalpy of a system increases

when energy is transferred to a constant-pressure system as heat

enthalpy of a system decreases

when energy leaves a constant-pressured system as heat

change in enthalpy is positive for

endothermic reactions

change in enthalpy is negative for

exothermic reactions

heat capacity at a constant volume, Cv

change in U / change in T

heat capacity at a constant pressure Cp

change in H / change in T

constant-volume and constant-pressure heat capacities of which two phases are similar

solids and liquids