Page 133 - Chemical equilibria Volume 4

Determination of the Values Associated with Reactions – Equilibrium Calculations 109
1
=
−
1
0
−
7.60 J.mol K ;
Δ s – standard entropy of vaporization of liquid copper at 298 K:
298
V
-1
– enthalpy of fusion of copper at 1357 K: Δ Fh 1357 = 741.6 J.mol
– specific heat capacity of solid copper at constant pressure:
−
−
+
−
1
3
1
C P (sol) = 1.30 3.52.10 T J.mol K
– specific heat capacity of liquid copper at constant pressure, independent
of the temperature:
−
−
1
1
C P (liq) = 1.79 J.mol K
– specific heat capacity of copper vapor at constant pressure, independent
of the temperature:
−
1
C P (vap ) = 1.189 J.mol K − 1
We shall express the term Δ (sublim) C = C (vap) − C P (sol) between 298 and
P
P
1357 K:
−
3
−
Δ (sublim) C =− 0.111 3.52.10 T
P
Let us express the term Δ C = C (vap ) − C P (l ) between 1357 K and
i
q
v
P
P
temperature T:
Δ C =− 0.605 J.mol K − 1
1
v
P
The standard enthalpy at T will be given by:
1357 T
ol
Δ v T 0 Δ h = v 298 ∫ h 0 + (s ) dT + ΔC F 1357 ∫ + Δ h v C P dT
P
298 1357
Thus, when we feed the specific heat capacities and the enthalpy of
fusion back into this formula, we obtain:
1357 T
Δ v T 0 Δ h = v 298 ∫ h 0 + ( 0.111 3.52.10 T− − − 3 ) dT + 741.6 − ∫ 0.605dT
298 1357