Problem 60
The standard entropies of \(\mathrm{CO}_{2}(\mathrm{~g}), \mathrm{C}(\mathrm{s})\) and \(\mathrm{O}_{2}(\mathrm{~g})\) are \(213.5,5.74\) and \(205 \mathrm{~J} \mathrm{~K}^{-1}\) respectively. The standard entropy of the formation of \(\mathrm{CO}_{2}(\mathrm{~g})\) is (a) \(1.16 \mathrm{JK}^{-1}\) (b) \(2.76 \mathrm{JK}^{-1}\) (c) \(1.86 \mathrm{JK}^{-1}\) (d) \(2.12 \mathrm{JK}^{-1}\)
Problem 62
The standard enthalpy of decomposition of \(\mathrm{N}_{2} \mathrm{O}_{4}\) to \(\mathrm{NO}_{2}\) is \(58.04 \mathrm{~kJ}\) and standard entropy of this reaction is \(176.7 \mathrm{~J} \mathrm{~K}^{-1}\). The standard free energy change for this reaction at \(25^{\circ} \mathrm{C}\), is (a) \(5.39 \mathrm{~kJ}\) (b) \(-5.39 \mathrm{~kJ}\) (c) \(539 \mathrm{~kJ}\) (d) \(53.9 \mathrm{~kJ}\)
Problem 63
The entropy values in \(\mathrm{J} \mathrm{K}^{-1} \mathrm{~mol}^{-1}\) of \(\mathrm{H}_{2}(\mathrm{~g})=130.6\), \(\mathrm{Cl}_{2}(\mathrm{~g})=223\) and \(\mathrm{HC} 1(\mathrm{~g})=186.7\) at \(298 \mathrm{~K}\) and 1 atm pressure. Then entropy change for the reaction \(\mathrm{H}_{2}(\mathrm{~g})+\mathrm{Cl}_{2}(\mathrm{~g}) \longrightarrow 2 \mathrm{HC} 1(\mathrm{~g})\) is (a) \(+540.3\) (b) \(+727.3\) (c) \(-166.9\) (d) \(+19.8\)
Problem 65
2 moles of an ideal gas is expanded isothermally and reversibly from 1 litre of 10 litre at \(300 \mathrm{~K}\). The enthalpy change (in \(\mathrm{kJ}\) ) for the process is (a) \(11.4 \mathrm{~kJ}\) (b) \(-11.4 \mathrm{~kJ}\) (c) \(0 \mathrm{~kJ}\) (d) \(4.8 \mathrm{~kJ}\).
Problem 66
The enthalpy of vaporization of a liquid is \(30 \mathrm{~kJ} \mathrm{~mol}^{-1}\) and entropy of vaporization is \(5 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K} .\) The boiling point of the liquid at 1 atm is (a) \(250 \mathrm{~K}\) (b) \(400 \mathrm{~K}\) (c) \(450 \mathrm{~K}\) (d) \(600 \mathrm{~K}\)
Problem 68
If the standard entropies of \(\mathrm{CH}_{4}, \mathrm{O}_{2}, \mathrm{CO}_{2}\) and \(\mathrm{H}_{2} \mathrm{O}\) are \(186.2,205.3,213.6\) and \(69.96 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\) respectively, then standard entropy change for the reaction \(\mathrm{CH}_{4}(\mathrm{~g})+2 \mathrm{O}_{2}(\mathrm{~g}) \longrightarrow \mathrm{CO}_{2}(\mathrm{~g})+2 \mathrm{H}_{2} \mathrm{O}\) (I) is (a) \(-215.6 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\) (b) \(-243.3 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\) (c) \(-130.5 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\) (d) \(-85.6 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\)
Problem 69
The standard entropy change for the reaction \(\mathrm{SO}_{2}(\mathrm{~g})+1 / 2 \mathrm{O}_{2}(\mathrm{~g}) \longrightarrow \mathrm{SO}_{3}(\mathrm{~g})\) is (where \(\mathrm{S}^{\circ}\) for \(\mathrm{SO}_{2}(\mathrm{~g}), \mathrm{O}_{2}(\mathrm{~g})\) and \(\mathrm{SO}_{3}(\mathrm{~g})\) are \(248.5,205\) and \(256.2\) \(\mathrm{J} \mathrm{K}^{-1} \mathrm{~mol}^{-1}\) respectively) (a) \(198.2 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\) (b) \(-192.8 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\) (c) \(-94.8 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\) (d) \(94.8 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\)
Problem 70
In thermodynamics, a process is called reversible when (a) surroundings and system change into each other (b) there is no boundary between system and surroundings (c) the surroundings are always in equilibrium with the system (d) the system changes into the surroundings sponta neously
Problem 71
Under the same conditions how many \(\mathrm{mL}\) of \(1 \mathrm{MKOH}\) and \(0.5 \mathrm{MH}_{2} \mathrm{SO}_{4}\) solutions, respectively, when mixed to form total volume of \(100 \mathrm{ml}\), produces the maximum rise in temperature? (a) 67,33 (b) 33,67 (c) 40,60 (d) 50,50
Problem 72
Identify the state function among the following: (a) \(\mathrm{Q}\) (b) \(\mathrm{Q}-\mathrm{w}\) (c) \(\mathrm{Q} / \mathrm{w}\) (d) \(\mathrm{Q}+\mathrm{w}\)
