For conversion of oxygen to ozone, at 298 K, the value of Kp for this conversion is 2.47 × 10–29. The value of ∆rG⊖ is-
1. | 163 kJ mol–1
|
2. | 153 kJ mol–1
|
3. | 178 kJ mol–1 | 4. | 169 kJ mol–1 |
Consider the following reaction at 298 K
For the above reaction, the standard Gibbs energy change, ∆rG⊖ at the given temperature is –13.6 kJ mol–1. The value of equilibrium constant is:
1. 6.4 × 105
2. 2.4 × 102
3. 4.4 × 102
4. 4.4 × 105
At 60°C, dinitrogen tetroxide is 50 percent dissociated. The standard free energy change at this temperature will be:
1. -863.8 kJmol-1
2. -652.7 kJmol-1
3. -763.8 kJmol-1
4. -789.9 kJmol-1
For the oxidation of iron,
4Fe(s) + 3O2 (g) → 2Fe2O3 (s)
entropy change is -549.4 JK-1 mol-1 at 298 K.
( for this reaction is )
The reaction is:
1. Spontaneous reaction
2. Non-spontaneous reaction
3. Reaction is an equilibrium
4. Cannot predict
(i) | When liquid crystallizes into a solid, entropy increases. |
(ii) | When the temperature of a crystalline solid is raised from 0 K to 115 K then entropy increases. |
(iii) | 2 NaHCO3 (s) →Na2CO3 (s) +CO2(g)+H2O(g); Entropy increases. |
(iv) | H2(g)→2H(g) ; Entropy decreases. |
The combustion of one mole of benzene takes place at 298 K and 1 atm. After combustion, CO2(g) and H2O (l)
are produced and 3267.0 kJ of heat is liberated.
The standard enthalpy of formation, ∆fH⊖ of benzene is:
(Standard enthalpies of formation of CO2(g) and are –393.5 kJ mol–1 and – 285.83 kJ mol–1 respectively.)
1. 54. 24 kJ mol–1
2. 48. 51 kJ mol–1
3. 66. 11 kJ mol–1
4. 15. 21 kJ mol–1
Assuming the water vapour to be a perfect gas. When 1 mol of water at 100°C and 1 bar pressure is converted to ice at 0°C, the change in internal energy is-
(The enthalpy of fusion of ice = 6.00 kJ mol-1 , heat capacity of water = 4.2 J/g°C)
1. 13.56 kJ mol-1
2. -12.16 kJ mol-1
3. -13.56 kJ mol-1
4. 12.16 kJ mol-1
A swimmer coming out from a pool is covered with a film of water weighing about 18g. The internal energy of vaporization at 298K. is-
∆vap H⊖ for water at 298K= 44.01kJ mol–1
1. 38.63 kJ
2. 43.82 J
3. 41.53 kJ
4. 40.33 J
1g of graphite is burnt in a bomb calorimeter in excess of oxygen at 298 K and 1 atmospheric pressure according to the equation
C (graphite) + O2(g) → CO2(g)
During the reaction, the temperature rises from 298 K to 299 K. If the heat capacity of the bomb calorimeter is 20.7kJ/K, the enthalpy change for the above reaction at 298 K and 1 atm is-
1. | – 2.48 ×102 kJ mol–1 | 2. | – 3.45 ×102 kJ mol–1 |
3. | – 1.65 ×102 kJ mol–1 | 4. | – 1.88 ×102 kJ mol–1 |
If water vapour is assumed to be a perfect gas, molar enthalpy change for vapourisation of 1 mol of water at 1 bar and 100°C is 41kJ mol–1. The internal energy change, when 1 mol of water is vapourised at 1 bar pressure and 100°C is:
1. 35.5 kJ mol–1
2. 37.9 kJ mol–1
3. 41 kJ mol–1
4. 44.2 kJ mol–1