Consider the following reactions:
\(\mathrm{S}_{(\mathrm{~g})}+\frac{3}{2} \mathrm{{O}_2}_{(\mathrm{~g})} \rightarrow \mathrm{{SO}_3}_{(\mathrm{~g})}+2 \mathrm{x} \mathrm{~kcal}\)

\(\mathrm{{SO}_2}_{(\mathrm{~g})}+\frac{1}{2} \mathrm{{O}_2}_{(\mathrm{~g})} \rightarrow \mathrm{{SO}_3}_{(\mathrm{~g})}+\mathrm{y} \mathrm{~kcal}\)
The heat of formation of SO2(g) is given by:
1. \(\dfrac{2 \mathrm{x}}{\mathrm{y}} \mathrm{kcal}\) 2. y - 2x kcal
3. 2x + y kcal 4. x + y kcal

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Find out the magnitude of work done in the process \(\mathrm{ABCD}\) (in \(\text{kJ}\)):
\(\mathrm{(1~atm~Lit=101.3~J)}\)
1. 304 2. 324
3. 360 4. 388
Subtopic:  First Law of Thermodynamics |
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Calculate the enthalpy change for the combustion of octane if the heat capacity of a bomb calorimeter is 5 kJ K⁻¹ and the temperature of the calorimeter increases by 5°C during combustion in excess oxygen.
 
1. 20 2. 25
3. 30 4. 35
Subtopic:  Enthalpy & Internal energy | Cp & Cv |
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One mole of an ideal gas expands from \(10 ~\mathrm{dm}^3\) to \(20 ~\mathrm{dm}^3\) through isothermal reversible process. Find \(\Delta U, q \) & \(w\):
1. \(\Delta U=0, q=0, w=0\) 2. \(\Delta U=0, q \neq 0, w \neq 0\)
3. \(\Delta \mathrm{U} \neq 0, \mathrm{q}=0, \mathrm{w} \neq 0\) 4. \(\Delta U \neq 0, q \neq 0, w=0\)
Subtopic:  First Law of Thermodynamics |
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Which of the following statement(s) is/are correct for the adiabatic process?
(A) Molar heat capacity is zero.
(B) Molar heat capacity is infinite.
(C) Work done on gas is equal to the increase in internal energy.
(D) The increase in temperature results in a decrease in internal energy.
 
1. (A) and (C)
2. (B) and (C)
3. (A) and (D)
4. (B) and (D)
Subtopic:  First Law of Thermodynamics |
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In an adiabatic process, the magnitude of work done in the case of one step & infinite steps follows the order:

1. \(\left|\mathrm{W}_{\text {rev }}\right|_{\text {expansion }}>\left|\mathrm{W}_{\text {Irrev }}\right|_{\text {expansion }}\)
2. \(\left|\mathrm{W}_{\text {rev }}\right|_{\text {expansion }}<\left|\mathrm{W}_{\text {Irrev }}\right|_{\text {expansion }}\)
3. \(\left|\mathrm{W}_{\text {rev }}\right|_{\text {expansion }}=\left|\mathrm{W}_{\text {Irrev }}\right|_{\text {expansion }}\)
4. Can't be predicted
Subtopic:  Thermodynamics' Properties and process |
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The standard enthalpy and entropy changes of decomposition of N2O4 to NO2 are 55.0 kJmol–1 and 175.0 JK–1 mol–1 respectively. The standard free energy change for this reaction at 25°C in J mol–1 is:
1. 2750 2. 2850
3. 2875 4. 2900
Subtopic:  Spontaneity & Entropy | Gibbs Energy Change |
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An ideal gas undergoes a cyclic transformation starting from the point A and coming back to the same point by tracing the path \(\mathrm{A} \rightarrow \mathrm{~B} \rightarrow \mathrm{C} \rightarrow \mathrm{D} \rightarrow \mathrm{~A}\) as shown in the three cases below:

Choose the correct option regarding change in internal energy, \(\Delta \mathrm{U} \):
1. \(\Delta \mathrm{U}\) (Case-III) > \(\Delta \mathrm{U}\) (Case-II) > \(\Delta \mathrm{U}\) (Case-I)
2. \(\Delta \mathrm{U}\) (Case-I) > \(\Delta \mathrm{U}\) (Case-II) > \(\Delta \mathrm{U}\) (Case-III)
3. \(\Delta \mathrm{U}\) (Case-I) > \(\Delta \mathrm{U}\) (Case-III) > \(\Delta \mathrm{U}\) (Case-II)
4. \(\Delta \mathrm{U}\) (Case-I) = \(\Delta \mathrm{U}\) (Case-II) = \(\Delta \mathrm{U}\) (Case-III) 
Subtopic:  Thermodynamics' Properties and process |
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Ice at –5°C is heated to convert into vapour with temperature of 110°C at atmospheric pressure. The entropy change associated with this process can be obtained from which of the following?
[Where: \(T_f\) is melting point and \(T_b\) is boiling point]

1. \(\int_{268 \mathrm{~K}}^{383 \mathrm{~K}} \mathrm{C}_{\mathrm{p}} \mathrm{dT}+\frac{\Delta \mathrm{H}_{\text {melting }}}{273}+\frac{\Delta \mathrm{H}_{\text {boiling }}}{373}\)

2. \(\int_{268 \mathrm{~K}}^{273 \mathrm{~K}} \frac{\mathrm{C}_{\mathrm{p}, \mathrm{~m}}}{\mathrm{~T}} \mathrm{dT}+\frac{\Delta \mathrm{H}_{\mathrm{m}}, \text { fusion }}{\mathrm{T}_{\mathrm{f}}}+\int_{273 \mathrm{~K}}^{373 \mathrm{~K}} \frac{\mathrm{C}_{\mathrm{p}, \mathrm{~m}} \mathrm{dT}}{\mathrm{~T}}+ \frac{\Delta \mathrm{H}_{\mathrm{m}, \text { vaporisation }}}{\mathrm{T}_{\mathrm{b}}}\)\(+\int_{373 \mathrm{~K}}^{383 \mathrm{~K}} \frac{\mathrm{C}_{\mathrm{p}, \mathrm{~m}} \mathrm{dT}}{\mathrm{~T}}\)

3. \(\int_{268 \mathrm{~K}}^{383 \mathrm{~K}} \mathrm{C}_{\mathrm{p}} \mathrm{dT}+\frac{\mathrm{q}_{\mathrm{rev}}}{\mathrm{~T}}\)

4. \(\begin{aligned} & \int_{268 \mathrm{~K}}^{273 \mathrm{~K}} \mathrm{C}_{\mathrm{p}, \mathrm{~m}} \mathrm{dT} +\int_{273 \mathrm{~K}}^{373 \mathrm{~K}} \mathrm{C}_{\mathrm{p}, \mathrm{~m}} \mathrm{dT}+\int_{373 \mathrm{~K}}^{383 \mathrm{~K}} \mathrm{C}_{\mathrm{p}, \mathrm{~m}} \mathrm{dT} \end{aligned}\)
Subtopic:  Cp & Cv | Spontaneity & Entropy |
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The bond dissociation enthalpy of X2 \(\Delta \mathrm{H}_{\mathrm{bond}}^{\mathrm{o}}\) in kJ mol–1 calculated from the given data is: 

\(\begin{aligned} &\small \mathrm{MX}(\mathrm{s}) \rightarrow \mathrm{M}^{+}(\mathrm{g})+\mathrm{X}^{-}(\mathrm{g}) ,\Delta \mathrm{H}_{\text {lattice }}=800 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \small \mathrm{M}(\mathrm{~s}) \rightarrow \mathrm{M}(\mathrm{~g}), \Delta \mathrm{H}_{\text {sub }}^{\circ}=100 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \small \mathrm{M}(\mathrm{~g}) \rightarrow \mathrm{M}^{+}(\mathrm{g})^{-}+\mathrm{e}^{-}(\mathrm{g}) \Delta \mathrm{H}_{\mathrm{i}}^{\circ}=500 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \small \mathrm{X}(\mathrm{~g})+\mathrm{e}^{-}(\mathrm{g}) \rightarrow \mathrm{X}^{-}(\mathrm{g}), \Delta \mathrm{H}_{\mathrm{eg}}^{\circ}=-300 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ &\small \mathrm{M}(\mathrm{~s})+\frac{1}{2} \mathrm{X}_2(\mathrm{~g}) \rightarrow \mathrm{M}^{+} \mathrm{X}^{-}(\mathrm{s}) ,\Delta \mathrm{H}_{\mathrm{f}}^{\circ}=-400 \mathrm{~kJ} \mathrm{~mol}^{-1} \end{aligned}\)
[Given: M+X is a pure ionic compound and X forms a diatomic
molecule X2 in the gaseous state]

1. 100
2. 150
3. 200
4. 250
Subtopic:  Hess's Law | Thermochemistry |
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