Thermodynamics · Question 10

Gas 'A' undergoes change from state 'X' to state 'Y'. In this process, the heat absorbed and work done by the gas is 10 J and 18 J respectively. Now gas is brought back to state 'X' by another process during which 6 J of heat is evolved. In the reverse process of 'Y' to 'X',

1. 18 J of the work is done by the gas 'A'.
2. 2 J of the work is done by the gas 'A'.
3. 12 J of the work is done on the gas 'A' by the surrounding.
4. 14 J of the work is done on the gas 'A' by the surrounding.

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

The plot of 10 K vs 1T gives a straight line. The intercept and slope respectively are (where K is the equilibrium constant).

1. - S R2.303, H R2.303
2. - H 2.303R, S 2.303R
3. S 2.303R, - H 2.303R
4. 2.303R H , 2.303R S

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

The heats of atomisation of methane and ethane are 'x' kJ mol-1 and 'y' kJ mol-1 respectively. The longest wavelength ( ) of light capable of breaking the C-C bond can be expressed in SI unit as :

1. NA hc250(y - 6x)
2. NA hc (y - 6x4 )-1
3. hc1000 ( y - 6x4 )-1
4. NA hc250(4y - 6x)

A cup of water at 5 C (system) is placed in a microwave oven and the oven is turned on for one minute during which the water begins to boil. Which of the following options is true?

1. q = +ve, w = -ve, U = +ve
2. q = +ve, w = 0, U = -ve
3. q = +ve, w = -ve, U = -ve
4. q = -ve, w = -ve, U = -ve

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

If the enthalpy of sublimation of Li is 155 kJ mol-1, enthalpy of dissociation of F2 is 150 kJ mol-1, ionization enthalpy of Li is 520 kJ mol-1, electron gain enthalpy of F is -313 kJ mol-1, standard enthalpy of formation of LiF is -594 kJ mol-1. The magnitude of lattice enthalpy of LiF is kJ mol-1. (Nearest Integer)

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

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

Use the following data : array|c|c|c| Substance & f H (500 K) kJ mol-1 & S (500 K) J K-1 mol-1 \ AB(g) & 32 & 222 \ A2(g) & 6 & 146 \ B2(g) & x & 280 \ array One mole each of A2(g) and B2(g) are taken in a 1 L closed flask and allowed to establish the equilibrium at 500 K. A2(g) + B2(g) 2AB(g) The value of x (in kJ mol-1) is . (Nearest integer) (Given : K = 2.2, R = 8.3 J K-1 mol-1)