020/2021

Total Marks : 100 Marks
Time : 1 hour and 15 minutes

1. A solution of HCI in water is 10.0% 110] by mass. Find the mole fraction 08110] in this solution.
(A) 0.036 (B) 0.051 (C) 0.012 (D) 0.060

2. A cylinder fitted with a frictionless piston contains 2.00 mol of He perfect gas at pressure
1.00 atm and is in a large constant-temperature bath at 500 K. The pressure is reversibly
increased to 10.00 atm. Calculate the work done on this process. (R = 8.314 J mol"! K-!)

(A) 191471 (B) 83147 (0) 831.47 (D) 191477

3. Which of this statement is incorrect for a fixed amount of a perfect gas ?
(A) Internal energy (U) and enthalpy (H) each depend only on T.
(8) PdV=nRdT for every infinitesimal process.
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(D) ता = (फ dT fora reversible process

4. Which of the following equation relates the chemical potential and the composition of a mixture ?
(A) Gibbs-Helmholtz (8) Joule-Thomson
(C) Debye-Huckel (D) Gibbs-Duhem

5. The change in entropy for reversible phase change (AH = +) at constant temperature and
pressure is
(A) Positive (B) Negative
(C) Zero (D) Either positive or negative
6. Identify the correct Clausius-Clapeyron equation from the following options (V, and ५;
are final and initial specific volumes, respectively) :

(A) “ರ್‌ (8) ता AH _
i Ve ம்‌ T(Vj- Vp)

(C) ‏نك‎ फा (D) त AH _
IT 100-517 dT T(Vj+Ve)

7. According 10 A, (g) ‏کے‎ 2A(ads), the Langmuir adsorption isotherm for the dissociative

adsorption of isotherm (where, ads = adsorbed, P is the partial pressure of A, and k is the
ratio of rate constant for adsorption and desorption) is

ke k 0
A = 8) 6= 0 = ற) 6=-
^) + © ‏پ 57 © کےا‎ 14+VkP
8. The equation, In y, = -z* |All)? is called the Debye-Hiickel limiting law

(I,, = molality-scale ionic strength; y, = molality-scale mean ionic activity coefficient).

Under which condition the experimental data show that the equation does give the correct
limiting behaviour for electrolyte solutions ?
(A) 1,71 (8) 1,70

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