Question
For vaporisation of water at 1 atm pressure, the values of ΔH and ΔS are 40.63 kJ mol- and 108.8 JK-1 mol-1, respectively. The temperature when Gibbs energy change (ΔG) for this transformation will be zero, is
-
273.14 K
-
393.4 K
-
373.4 K
-
293.4 K
Solution
C.
373.4 K
ΔG = ΔH - TΔS
ΔG = 0 (given)
ΔH = TΔS,
T = 40.63 x 103 / 108.8 = 373.4 K