Q1 · 2005-2021 · 2 marks
Standard entropy of crystalline carbon monoxide (in \mathrm{J/mol}) at 0\,\mathrm{K} is around
- (a) 0.03
- (b) 2.50
- (c) Zero
- (d) 5.76
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Answer: (d)
GATE Chemistry (CY) — Chemical Thermodynamics previous year questions
15 questions · 2005 · all with verified answer · last checked 2026-11-10
Q2 · 2005-2021 · 2 marks
The specific volume of liquid water is 1.001 \mathrm{~mL} \mathrm{~g}^{-1} and that of ice is 1.0907 \mathrm{~mL} \mathrm{~g}^{-1} at { }^{\circ} \mathrm{C}. If the heat of fusion of ice at this temperature is 333.88 \mathrm{~J} \mathrm{~g}^{-1}, the rate of change of melting point of ice with pressure in \mathrm{deg} \mathrm{atm}^{-1} will be
- (a) -0.0075
- (b) 0.0075
- (c) 0.075
- (d) -0.075
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Answer: (a)
Q3 · 2005-2021 · 2 marks
The correct statement(s) among the following is/are (i) The vibrational energy levels of a real diatomic molecule are equally spaced. (ii) At 500 K, the reaction A \rightarrow B is spontaneous when \Delta H = 18.83\ \mathrm{kJ\,mol^{-1}} and \Delta S = 41.84\ \mathrm{J\,K^{-1}\,mol^{-1}}. (iii) The process of fluorescence involves transition from a singlet electronc state to another singlet electronic state by absoprtion of light. (iv) When a constant P is added to each of the possible energies of a system, its entropy remains unchanged.
- (a) Only i
- (b) Only ii
- (c) Both i and iii
- (d) Both ii and iv
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Answer: (c)
Q4 · 2005-2021 · 2 marks
If a gas obeys the equation of state P(V - nb) = nRT, the ratio \frac{(C_P - C_V)}{(C_P - C_V)_{\text{ideal}}} is:
- (a) >1
- (b) <1
- (c) 1
- (d) (1 - b)
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Answer: (c)
Q5 · 2005-2021 · 2 marks
The free energy change (\Delta G) of 1 mole of an ideal gas that is compressed isothermally from 1 atm to 2 atm is:
- (a) RT\ln 2
- (b) -2RT
- (c) -RT\ln 2
- (d) 2RT
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Answer: (a)
Q6 · 2005-2021 · 2 marks
The molar entropy of crystalline CO at absolute zero is
- (a) Zero
- (b) -R\ln 2
- (c) R\ln 2
- (d) 2R\ln 2
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Answer: (a)
Q7 · 2005-2021 · 2 marks
The change in entropy when two moles of Argon gas are heated at constant volume from 300 K to 500 K is:
- (a) -12.74\ \mathrm{J\,K^{-1}\,mole^{-1}}
- (b) -6.37\ \mathrm{J\,K^{-1}\,mole^{-1}}
- (c) 6.37\ \mathrm{J\,K^{-1}\,mole^{-1}}
- (d) 12.74\ \mathrm{J\,K^{-1}\,mole^{-1}}
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Answer: (c)
Q8 · 2005-2021 · 2 marks
At any temperature T, fugacity coefficient (\gamma) is given by
\ln\gamma=\int_{0}^{P}\frac{Z-1}{P'}\,\mathrm{d}P'
where Z is the compressibility factor. The fugacity coefficient of a real gas governed by equations of state, P(V-b)=RT with ‘b’ a constant is given by - (a) \frac{RT}{bP}
- (b) e^{\frac{RT}{bP}}
- (c) \frac{bP}{RT}
- (d) e^{\frac{bP}{RT}}
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Answer: (d)
Q9 · 2005-2021 · 2 marks
\left(\frac{\partial G}{\partial P}\right)_T =
- (a) V
- (b) S
- (c) -S
- (d) -V
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Answer: (a)
Q10 · 2005-2021 · 2 marks
For the process
1\,\mathrm{Ar}(300\,\mathrm{K}, 1\,\mathrm{bar}) \longrightarrow 1\,\mathrm{Ar}(200\,\mathrm{K}, 10\,\mathrm{bar})
assuming ideal gas behavior, the change in molar entropy is: - (a) -27.57\ \mathrm{J\,K^{-1}\,mol^{-1}}
- (b) +27.57\ \mathrm{J\,K^{-1}\,mol^{-1}}
- (c) -24.20\ \mathrm{J\,K^{-1}\,mol^{-1}}
- (d) +24.20\ \mathrm{J\,K^{-1}\,mol^{-1}}
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Answer: (a)
Q11 · 2005-2021 · 2 marks
The maximum non-PV work that a system can perform at constant P is
- (a) \Delta H
- (b) \Delta G
- (c) \Delta S
- (d) \Delta A
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Answer: (b)
Q12 · 2005-2021 · 2 marks
Consider the reaction:
\mathrm{A + B \rightleftharpoons C}
The unit of the thermodynamic equilibrium constant for the reaction is - (a) \mathrm{mol\,L^{-1}}
- (b) \mathrm{L\,mol^{-1}}
- (c) \mathrm{mol^2\,L^{-2}}
- (d) dimensionless
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Answer: (d)
Q13 · 2005-2021 · 2 marks
33.2\ \mathrm{kJ\ mol^{-1}}, the enthalpy change for the reaction 2\mathrm{NO}(\mathrm{g})+\mathrm{O}_2(\mathrm{g})(\mathrm{g})\rightarrow 2\mathrm{NP}_2(\mathrm{g}) is
- (a) 16.6\ \mathrm{kJ}
- (b) -57.1\ \mathrm{kJ}
- (c) -114.2\ \mathrm{kJ}
- (d) 57.1\ \mathrm{kJ}
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Answer: (b)
Q14 · 2005-2021 · 2 marks
Which one of the following defines the absolute temperature of a system?
- (a) \left(\frac{\partial U}{\partial S}\right)_V
- (b) \left(\frac{\partial A}{\partial S}\right)_V
- (c) \left(\frac{\partial H}{\partial S}\right)_V
- (d) \left(\frac{\partial G}{\partial S}\right)_V
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Answer: (a)
Q15 · 2005-2021 · 2 marks
For a system subjected to only P-V work, entropy is given by (I) -\left(\frac{\partial G}{\partial T}\right)_P (II) \left(\frac{\partial G}{\partial P}\right)_T (III) -\left(\frac{\partial A}{\partial V}\right)_T (IV) -\left(\frac{\partial A}{\partial T}\right)_V
- (a) I and II
- (b) I and IV
- (c) I only
- (d) II only
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Answer: (a)
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