Problem 38
The amount of heat required to raise the temperature of one mole of the substance through \(1 \mathrm{~K}\) is called, its (a) molar heat (b) entropy (c) thermal capacity (d) specific heat
Problem 39
Bond energy of \(\mathrm{N}-\mathrm{H}, \mathrm{H}-\mathrm{H}\), and \(\mathrm{N} \equiv \mathrm{N}\) bonds are \(\mathrm{Q}_{1}\), \(\mathrm{Q}_{2}\) and \(\mathrm{Q}_{3} ; \Delta \mathrm{H}\) of \(\mathrm{N}_{2}+3 \mathrm{H}_{2} \longrightarrow 2 \mathrm{NH}_{3}\) is (a) \(\mathrm{Q}_{3}+3 \mathrm{Q}_{2}-2 \mathrm{Q}_{1}\) (b) \(2 Q_{1}-Q_{3}-2 Q_{2}\) (c) \(\mathrm{Q}_{3}+3 \mathrm{Q}_{2}-6 \mathrm{Q}_{1}\) (d) \(Q_{1}+Q_{2}-Q_{3}\)
Problem 40
Which of the following gas molecule has the maxi mum specific heat at constant pressure? (a) helium (b) argon (c) nitrogen (d) oxygen
Problem 41
A reaction occurs spontaneously if (a) \(\mathrm{T} \Delta \mathrm{S}<\Delta \mathrm{H}\) and both \(\Delta \mathrm{H}, \Delta \mathrm{S}\) are \(+\mathrm{ve}\) (b) \(\mathrm{T} \Delta \mathrm{S}>\Delta \mathrm{H}\) and \(\Delta \mathrm{H}=+\mathrm{ve}, \Delta \mathrm{S}=-\mathrm{ve}\) (c) \(\mathrm{T} \Delta \mathrm{S}>\Delta \mathrm{H}\) and both \(\Delta \mathrm{H}, \Delta \mathrm{S}\) are \(+\mathrm{ve}\) (d) \(\mathrm{T} \Delta \mathrm{S}=\Delta \mathrm{H}\) and both \(\Delta \mathrm{H}, \Delta \mathrm{S}\) are \(+\mathrm{ve}\)
Problem 42
For the reaction of one mole of \(\mathrm{Zn}\) dust with one mole of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) in a bomb calorimeter, \(\Delta \mathrm{U}\) and \(\mathrm{w}\) corresponds to (a) \(\Delta U<0, w=0\) (b) \(\Delta U<0, w<0\) (c) \(\Delta U>0, w=0\) (d) \(\Delta U>0, w>0\)
Problem 43
For a phase change \(\mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \stackrel{{ }^{\circ} \mathrm{C}, 1 \mathrm{bar}}{\longrightarrow} \mathrm{H}_{2} \mathrm{O}(\mathrm{s})\) (a) \(\Delta \mathrm{G}=0\) (b) \(\Delta \mathrm{S}=0\) (c) \(\Delta \mathrm{H}=0\) (d) \(\Delta \mathrm{U}=0\)
Problem 44
Standard enthalpy and standard entropy changes for the oxidation of ammonia at \(298 \mathrm{~K}\) are \(-382.64 \mathrm{~kJ}\) \(\mathrm{mol}^{-1}\) and \(-145.6 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}\), respectively. Standard Gibbs energy change for the same reaction at \(268 \mathrm{~K}\) is (a) \(-221.1 \mathrm{~kJ} \mathrm{~mol}^{-1}\) (b) \(-339.3 \mathrm{~kJ} \mathrm{~mol}^{-1}\) (c) \(-439.3 \mathrm{kJmol}^{-1}\) (d) \(-523.2 \mathrm{~kJ} \mathrm{~mol}^{-1}\)
Problem 45
The molar heat capacity of water at constant pressure, \(\mathrm{C}\), is \(75 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}\). When \(1.0 \mathrm{~kJ}\) of heat is supplied to \(100 \mathrm{~g}\) of water which is free to expand, the increase in temperature of water is (a) \(4.8 \mathrm{~K}\) (b) \(6.6 \mathrm{~K}\) (c) \(1.2 \mathrm{~K}\) (d) \(2.4 \mathrm{~K}\)
Problem 46
What is the entropy change (in \(\mathrm{JK}^{-1} \mathrm{~mol}^{-1}\) ) when \(1 \mathrm{~mol}\) of ice is converted into water at \(0^{\circ} \mathrm{C} ?\) (The enthalpy change for the conversion of ice to liquid water is \(6.0\) \(\mathrm{kJ} \mathrm{mol}^{-1}\) at \(0^{\circ} \mathrm{C}\) ) (a) \(2.198\) (b) \(21.98\) (c) \(20.13\) (d) \(2.013\)
Problem 47
For the reaction, \(\mathrm{C}_{3} \mathrm{H}_{8}(\mathrm{~g})+5 \mathrm{O}_{2}(\mathrm{~g}) \longrightarrow 3 \mathrm{CO}_{2}(\mathrm{~g})+4 \mathrm{H}_{2} \mathrm{O}\) (I) at constant temperature, \(\Delta \mathrm{H}-\Delta \mathrm{E}\) is (a) \(+3 \mathrm{RT}\) (b) \(-\mathrm{RT}\) (c) \(+\mathrm{RT}\) (d) \(-3 \mathrm{RT}\)
