In which process net work done is zero?
Cyclic
Isobaric
Adiabatic
Free expansion
When the heat of a reaction at constant pressure is -2.5 × 103 cals and entropy change for the reaction is 7.4 cal deg -1, it is predicted that the reaction at 25ºC is
reversible
spontaneous
non - spontaneous
irreversible
For a particular reversible reaction at temperature T, ∆H and ∆S were found to be both +ve. If Te is the temperature at equilibrium, the reaction would be spontaneous when
Te > T
T > Te
Te is 5 times T
T = Te
For the process
H2O(I) ( 1 bar, 273 K) → H2O(g) (1 bar, 373 K)
The correct set of thermodynamic parameters is
∆G = 0,∆S = +ve
∆G = 0, ∆S = -ve
∆G = +ve, ∆S = 0
∆G = -ve, ∆S = +ve
What will be the change of entropy ΔrS° at 298 K for the reaction in which urea is formed from NH3 and CO2?2NH3 (g) + CO2 (g) → NH2CONH2(aq) + H2O(l)[Given the standard entropy of NH2CONH2(aq), CO2 (g), NH3 (g) and H2O(l) are 174.0, 213.7, 192.3 and 69.9 J K-1 mol-1 respectively]
200 JK-1 mol-1
-35.44 JK-1 mol-1
-354.4 JK-1 mol-1
425.2 JK-1 mol-1
Identify the correct statement regarding a spontaneous process
Lowering of energy in the reaction process is the only criterion for spontaneity
For a spontaneous process in an isolated system, the change in entropy is positive.
Endothermic reactions are never spontaneous
Exothermic reaction are always spontaneous.
When the system is returned from state B to A along the curved path, work done on the system is 20J. Does the system absorb or liberate heat, and how much?
System liberates heat, -70J
System absorbs heat, 70J
System absorbs heat, 90J
System liberates heat, -90J
The Gibbs energy for the decomposition of Al2O3 at 500°C is as follows
∆rG = + 966 kJ mol -1
The potential difference needed for electrolytic reduction of Al2O3 at 500oC is at least
4.5 V
3.0 V
2.5 V
5.0 V
Internal energy and pressure of a gas of unit volume are related as
