Thermodynamics · Question 7

If 3.365 g of ethanol (l) is burnt completely in a bomb calorimeter at 298.15 K, the heat produced is 99.472 kJ. The | Hf | of ethanol at 298.15 K is 102 kJ mol-1. (Nearest integer) Given: Standard enthalpy for combustion of graphite = −393.5 kJ mol-1 Standard enthalpy of formation of water (l) = −285.8 kJ mol-1 Molar mass in g mol-1 of C, H, O are 12, 1 and 16 respectively

Consider the following data. (i) 2Al(s) + 6HCl(aq) Al2Cl6(aq) + 3H2(g) + 1200 kJ/mol (ii) H2(g) + Cl2(g) 2HCl(g) + 164 kJ/mol (iii) HCl(g) + aq HCl(aq) + 83 kJ/mol (iv) Al2Cl6(s) + aq Al2Cl6(aq) + 663 kJ/mol The enthalpy of formation of anhydrous solid Al2Cl6 is :

1. -648 kJ mol-1
2. -1350 kJ mol-1
3. -2002 kJ mol-1
4. -1527 kJ mol-1

At the transition temperature T, A B and G = 105 - 35 T where A and B are two states of substance X. The transition temperature in °C when pressure is 1 atm is . (Nearest integer)

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