Thermodynamics

The enthalpy of formation of ethane (C2H6) from ethylene by addition of hydrogen where the bond-energies of C-H, C-C, C=C, H-H are 414 kJ, 347 kJ, 615 kJ and 435 kJ respectively is − kJ

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

For a certain reaction at 300 K, K = 10, then for the same reaction is − 10-1 kJ mol-1. (Given R = 8.314 J K-1 mol-1)

Consider the following reaction at 298 K: 32O2(g) O3(g); KP = 2.47 10-29. rG for the reaction is kJ. (Given R = 8.314 JK-1 mol-1)

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.

Two reactions are given below: 2Fe(s) + 32O2(g) Fe2O3(s), H = -822 kJ/mol C(s) + 12O2(g) CO(g), H = -110 kJ/mol Then enthalpy change for following reaction 3C(s) + Fe2O3(s) 2Fe(s) + 3CO(g) is kJ/mol.

Which of the following is not correct?

1. G is positive for a spontaneous reaction
2. G is positive for a non-spontaneous reaction
3. G is zero for a reversible reaction
4. G is negative for a spontaneous reaction

Standard enthalpy of vapourisation for CCl4 is 30.5 kJ mol-1. Heat required for vapourisation of 284 g of CCl4 at constant temperature is kJ. (Given molar mass in g mol-1; C = 12, Cl = 35.5)