Problem 12
Internal energy (E) and pressure of a gas of unit volume are related as (a) \(\mathrm{P}=\frac{2}{3} \mathrm{E}\) (b) \(\mathrm{P}=\frac{3}{2} \mathrm{E}\) (c) \(\mathrm{P}=\frac{\mathrm{E}}{2}\) (d) \(\mathrm{P}=2 \mathrm{E}\)
Problem 13
Which one of the following statements is false? (a) temperature is a state function (b) work is a state function (c) change in the state depends upon initial and final state (d) work appears at the boundary of the system
Problem 14
Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is (a) \(\Delta \mathrm{S}_{\text {system }}+\Delta \mathrm{S}_{\text {surroundings }}>0\) (b) \(\Delta \mathrm{S}_{\text {system }}-\Delta \mathrm{S}_{\text {surroundings }}>0\) (c) \(\Delta \mathrm{S}_{\text {system }}>0\) (d) \(\Delta \mathrm{S}_{\text {surroundings }}>0\)
Problem 15
For which of the following processes will the entropy increase? (a) reaction of magnesium with oxygen to form magnesium oxide (b) reaction of nitrogen and hydrogen to form ammonia (c) sublimation of dry ice (d) condensation of steam
Problem 16
Which of the following is correct equation? (a) \(\Delta \mathrm{U}=\Delta \mathrm{Q}-\mathrm{W}\) (b) \(\Delta \mathrm{W}=\Delta \mathrm{U}+\Delta \mathrm{Q}\) (c) \(\Delta \mathrm{U}=\Delta \mathrm{W}+\Delta \mathrm{Q}\) (d) none of these
Problem 17
For a reaction to occur spontaneously (a) \((\Delta \mathrm{H}-\mathrm{T} \Delta \mathrm{S})\) must be negative (b) \((\Delta \mathrm{H}+\mathrm{T} \Delta \mathrm{S})\) must be negative (c) \(\Delta \mathrm{H}\) must be negative (d) \(\Delta \mathrm{S}\) must be negative
Problem 18
Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction? (a) exothermic and increasing disorder (b) exothermic and decreasing disorder (c) endothermic and increasing disorder (d) endothermic and decreasing disorder
Problem 20
Assume each reaction is carried out in an open container. For which reaction \(\Delta \mathrm{H}=\Delta \mathrm{U} ?\) (a) \(\mathrm{PC} 1_{5}(\mathrm{~g}) \longrightarrow \mathrm{PCl}_{3}(\mathrm{~g})+\mathrm{Cl}_{2}(\mathrm{~g})\) (b) \(2 \mathrm{CO}(\mathrm{g})+\mathrm{O}_{2}(\mathrm{~g}) \longrightarrow 2 \mathrm{CO}_{2}(\mathrm{~g})\) (c) \(\mathrm{H}_{2}(\mathrm{~g})+\mathrm{Br}_{2}(\mathrm{~g}) \longrightarrow 2 \mathrm{HBr}(\mathrm{g})\) (d) \(\mathrm{C}(\mathrm{s})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{g}) \longrightarrow 2 \mathrm{H}_{2}(\mathrm{~g})+\mathrm{CO}_{2}(\mathrm{~g})\)
Problem 21
Identify the correct statement regarding entropy. (a) at absolute zero temperature, entropy of a perfectly crystalline substance is +ve. (b) at absolute zero temperature, entropy of a perfectly crystalline substance is taken to be zero (c) at absolute zero temperature, entropy of all crystalline substances in taken to be 0 . (d) at \(0^{\circ} \mathrm{C}\), entropy of a perfectly crystalline substance is taken to be 0 .
Problem 22
Standard molar enthalpy of formation of \(\mathrm{CO}_{2}\) is equal to (a) standard molar enthalpy of combustion of carbon (graphite) (b) standard molar enthalpy of combustion of gaseous carbon (c) sum of standard molar enthalpies of formation of \(\mathrm{CO}\) and \(\mathrm{O}_{2}\) (d) zero
