Thermodynamics · Question 78

At a certain temperature, T(K), during a process, 500 J is absorbed by the system and work of 200 J is done by the system. Then change in internal energy of the system is :

1. 700 J
2. 400 J
3. 300 J
4. 500 J

Consider the following reaction : 2A(g) + B(g) 2D(g) U = −10 kJ mol-1 and S = −44 J K-1 at 298 K. Identify the correct option with G for the reaction and spontaneity of the reaction at 298 K. (Given : R = 8.31 J mol-1 K-1)

1. +0.63568 kJ mol-1, non-spontaneous
2. −0.63568 kJ mol-1, spontaneous
3. −1.635 kJ mol-1, spontaneous
4. +1.635 kJ mol-1, non-spontaneous

Two moles of an ideal gas undergo free expansion from 10 L to 100 L at 300 K. The values of Ssystem and Ssurroundings are (R is universal gas constant)

1. Ssystem = 4.606 R; Ssurroundings = 0
2. Ssystem = 0; Ssurroundings = 0
3. Ssystem = 4.606 R; Ssurroundings = -4.606 R
4. Ssystem = 0; Ssurroundings = 4.606 R

Consider the reversible processes for 1.0 mol of an ideal gas as shown in the figure. [figure] w1, w2, w3 and w4 represent work done (in calories) in the processes 1, 2, 3 and 4, respectively; U2 and U4 are changes in the internal energy for the processes 2 and 4, respectively. [use R = 2 cal K-1 mol-1] The correct option is

1. w1 + w2 + w3 + w4 = 0
2. w1 + w3 = -2T1 V2V1 - 2T2 V4V3
3. w2 + w4 = U2 - U4
4. w1 + w2 = 2T1 V2V1

A protein undergoes reversible thermal denaturation from its initial state N to denatured state D according to N D. At 60 C, the concentrations of both N and D are equal at equilibrium, and the standard enthalpy change of denaturation is 666 kJ mol-1. The standard entropy change ( S in kJ K-1 mol-1) of the protein upon denaturation at 60 C is closest to

1. 11.1
2. 2.0
3. 2000.0
4. 333.0

The standard heat of formation, in kcal/mol of Ba2+ is : [Given : standard heat of formation of SO42- ion (aq) = -216 kcal/mol, standard heat of crystallisation of BaSO4(s) = -4.5 kcal/mol, standard heat of formation of BaSO4(s) = -349 kcal/mol]

1. +133.0
2. +220.5
3. -128.5
4. -133.0

C(s) + 2H2(g) CH4(g); H = -74.8 kJ mol-1. Which of the following diagrams gives an accurate representation of the above reaction? [R reactants; P products]

1. [figure]
2. [figure]
3. [figure]
4. [figure]

In which of the following processes entropy increases? Choose the correct answer from the options given below:

1. A and C
2. A, B and D
3. A, C and D
4. C and D

Match List I with List II. Choose the correct answer from the options given below:

1. A-IV, B-III, C-II, D-I
2. A-IV, B-II, C-III, D-I
3. A-I, B-II, C-III, D-IV
4. A-II, B-III, C-IV, D-I

The work done during reversible isothermal expansion of one mole of hydrogen gas at 25 from pressure of 20 atmosphere to 10 atmosphere is (Given R = 2.0 cal K-1 mol-1)

1. 0 calorie
2. -413.14 calories
3. 413.14 calories
4. 100 calories