We are trying to show entropy gives rise to presssure. Imagine a box with volume V is divided into M smaller cubic boxes with volume Vo and N particles are distributed in the box. Assuming N << M, show that P=TdS/dV can be approximated to P=NkBT/V, where V=VoxM
more so, S=KblnW(N:M)
and that the first law of thermo is TdS=U+PdV-udN, but N and U are constants
According to the first law of thermodynamics: TdS = U + PdV - udN
Here, U and N are constants, then the following expressions can be written.
U = 0
And dN = 0
Therefore, from the first law of thermodynamics, TdS = PdV
Hence, P = TdS/dV
We are trying to show entropy gives rise to presssure. Imagine a box with volume V...
02) Consider a hydrostatic system represented by the thermodynamic variables volume V, pressure P and temperature T. a) Consider entropy S = S(T, V) and derive the equation TdS. Tas = Cvat +T (1) dV. V Show that this equation can be written as follows BT TdS = CydT + PDV where Cv is the thermal capacity at constant volume, B is the isobaric expansiveness and K is isothermal compressibility: b) Consider a gas described by the equation of state...
The Sackur-Tetrode Equation gives the entropy of a sample of n moles of monatomic ideal gas as a function of its internal energy U and volume V S(U, V) = 5/2 n R + n R In (V/n N_A(4piM U/3nN^2_Ah^2)^3/2) In the equation, R is the gas constant, M is the molar mass, N_4 is Avogadro's number, and h is Plank's constant. The equation can be derived using S = k ln W and directly computing W, the number of...
1. Quick Exercises (a) In lecture 15, we showed that the canonical partition function, Q, is related to the Helmholz free energy: A = -kTinQ. Using the fundamental thermo- dynamic relation of Helmheltz free energy (i.e. dA = -SIT - PdV + pdN), express P, and u in terms of Q. (b) The canonical partition function for N non-interacting, indistinguishable parti- cles in volume V at temperature T is given by Q(N, V,T) = where where 9(V, T) is the...
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