Calorimetric calculations:

( )

( )

dQ mcdT or dQ nCdT specific heat

Q mL latent heat

General Formulas applicable to ALL processes in an Ideal Gas:

V

PV nRT

dU dQ dW

dW PdV

dU nC dT

3

( )2V

P V

C R monoatomic

C C R

Specific Processes: Isothermal: T=constant dT = 0 dU =0 dQ=dW

lnf f

f

ii i

VnRTW PdV dV nRT

V V

Adiabatic: dQ=0 dU= -dW

f

V V f i

i

dW dU W nC dT nC T T

1

PV const

TV const

Isobaric: P=constant

f

f i

i

W PdV P V V

Isochroic: V=constant dV=0 dW=0 dU=dQ

Entropy: General Reversible Processes: dS=dQ/T ln lnV f i f iS nC T T nR V V

Calorimetric Processes:

( ) :

ln ln

( ) :

remains constant at phase change

f f

i i

specific heat dQ mcdT or dQ nCdT

dT dTdS mc or nC

T TT T

S mc or nCT T

latent heat Q mL

mLS T

T

Non Reversible Processes: (one cannot write dS=dQ/T for the process)

But one can use a surrogate reversible process with the same initial and final states to calculate S . 2nd Law of Thermodynamics: 0tot system environmentS S S