Thermodynamics

Arrange the following isothermal processes in order of the magnitude of the work (p − V) involved between states 1 and 2. Choose the correct option.

1. |wB| > |wA| > |wC| > |wD|
2. |wC| > |wD| > |wA| > |wB|
3. |wC| > |wD| > |wB| > |wA|
4. |wB| > |wA| > |wD| > |wC|

Match List - I with List - II. Given V1 and V2 are initial and final volumes respectively. Choose the correct answer from the options given below :

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

20.0 dm3 of an ideal gas 'X' at 600 K and 0.5 MPa undergoes isothermal reversible expansion until pressure of the gas is 0.2 MPa. Which of the following option is correct? (Given: 2 = 0.3010 and 5 = 0.6989)

1. w = -9.1 kJ, U = 0, H = 0, q = 9.1 kJ
2. w = 9.1 J, U = 9.1 J, H = 0; q = 0
3. w = -3.9 kJ, U = 0, H = 0; q = 3.9 kJ
4. w = +4.1 kJ, U = 0, H = 0; q = -4.1 kJ

Match the LIST-I with LIST-II Choose the correct answer from the options given below:

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

Match the LIST-I with LIST-II Choose the correct answer from the options given below :

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

Which of the following graphs between pressure 'p' versus volume 'V' represents the maximum work done?

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

One mole of an ideal gas expands isothermally and reversibly from 10 dm3 to 20 dm3 at 300 K. U, q and work done in the process respectively are Given: R = 8.3 J K-1 mol-1 10 = 2.3 2 = 0.30 3 = 0.48

1. 0, 21.84 kJ, -1.726 J
2. 0, 21.84 kJ, 21.84 kJ
3. 0, 1.718 kJ, -1.718 kJ
4. 0, -17.18 kJ, 1.718 J

A perfect gas (0.1 mol) having Cv = 1.50 R (independent of temperature) undergoes the following transformation from point 1 to point 4. If each step is reversible, the total work done (w) while going from point 1 to point 4 is (-) J (nearest integer) [Given: R = 0.082 L atm K-1 mol-1] [figure]

[figure] Two vessels A and B are connected via stopcock. The vessel A is filled with a gas at a certain pressure. The entire assembly is immersed in water and is allowed to come to thermal equilibrium with water. After opening the stopcock the gas from vessel A expands into vessel B and no change in temperature is observed in the thermometer. Which of the following statement is true ?

1. dq 0
2. The pressure in the vessel B before opening the stopcock is zero
3. dw 0
4. dU 0

Arrange the following in order of magnitude of work done by the system/on the system at constant temperature. (a) | wreversible| for expansion in infinite stages. (b) | wirreversible| for expansion in single stage. (c) | wreversible| for compression in infinite stages. (d) | wirreversible| for compression in single stage. Choose the correct answer from the options given below:

1. d > c = a > b
2. c = a > d > b
3. a > c > b > d
4. a > b > c > d

[figure] Consider the figure provided. 1 mol of an ideal gas is kept in a cylinder, fitted with a piston, at the position A, at 18°C. If the piston is moved to position B, keeping the temperature unchanged, then 'x' L atm work is done in this reversible process. x = L atm. (nearest integer) [Given : Absolute temperature = °C + 273.15, R = 0.08206 L atm mol-1 K-1]

An ideal gas, Cv = 52R, is expanded adiabatically against a constant pressure of 1 atm until it doubles in volume. If the initial temperature and pressure is 298 K and 5 atm, respectively then the final temperature is K (nearest integer). [ cv is the molar heat capacity at constant volume]

Three moles of an ideal gas are compressed isothermally from 60 L to 20 L using constant pressure of 5 atm. Heat exchange Q for the compression is - Lit. atm.

Choose the correct option for free expansion of an ideal gas under adiabatic condition from the following :

1. q = 0, T = 0, w = 0
2. q = 0, T 0, w = 0
3. q 0, T = 0, w = 0
4. q = 0, T < 0, w 0

If 5 moles of an ideal gas expands from 10 L to a volume of 100 L at 300 K under isothermal and reversible condition then work, w, is −x J. The value of x is . (Given R = 8.314 J K-1 mol-1)

[figure] An ideal gas undergoes a cyclic transformation starting from the point A and coming back to the same point by tracing the path A B C A as shown in the diagram above. The total work done in the process is J.

If three moles of an ideal gas at 300 K expand isothermally from 30 dm3 to 45 dm3 against a constant opposing pressure of 80 kPa, then the amount of heat transferred is J.