Thermodynamics · Question 1

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

Choose the correct statement for the work done in the expansion and heat absorbed or released when 5 litres of an ideal gas at 10 atmospheric pressure isothermally expands into vacuum until volume is 15 litres :

1. Both the heat and work done will be greater than zero
2. Heat absorbed will be less than zero and work done will be positive
3. Work done will be zero and heat will also be zero
4. Work done will be greater than zero and heat will remain zero