The enthalpy of combustion of H2, cyclohexene (C6H10) and cyclohexane (C6H12) are - 241, -3800 and -3920 kJ per mol respectively. Heat of hydrogenation of cyclohexene is
- 121 kJ per mol
+ 121 kJ per mol
+ 242 kJ per mol
- 242 kJ per mol
In a closed insulated container a liquid is stirred with a paddle to increase the temperature, which of the following is true ?
E = W ≠ 0, q = 0
E = W = 0, q = 0
E =0,W =q ≠ 0
W =0,E =q ≠ 0
Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is
Ssystem + Ssurrounding > 0
Ssystem - Ssurrounding > 0
Ssystem > 0 only
Ssurrounding > 0 only
For the reaction,
C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(l) at constant temperature, H - E is
+ 3RT
- RT
+ RT
- 3RT
From the given reactions
the heat of formation of SO2 is
One mole of an ideal gas at 300K is expanded isothermally from an initial volume of 1 L to 10 L. The E for this process is (R = 2 cal mol-1 K-1 )
163.7 cal
zero
1381.1 cal
9 L atm
Consider the following reactions
(i) H+ (aq) + OH- (aq) = H2O(l) - x1 kJ mol-1
(ii) H2(g) + O2 (g) = H2O (l) x2 kJ mol-1
(iii) CO2 (g) + H2 (g) = CO (g) + H2O(l) -x3 kJ mol-1
(iv) C2H2(g) + O(g) = 2CO2 (g) + H2O (l) + x4 kJ mol-1
Enthalpy of formation of H2O(l) is
- x2 kJ mol-1
+x3 kJ mol-1
-x4 kJ mol-1
+x1 kJ mol-1
Identify the correct statement regarding entropy.
At absolute zero temperature, entropy of a perfectly crystalline substance is taken to be zero
At absolute zero temperature, the entropy of a perfectly crystalline substance is +ve
At absolute zero temperature, the entropy of all crystalline substances is to be zero
At 0o C, the entropy of a perfectly crystalline substance is taken to be zero
When 1 mole gas is heated at constant volume, temperature is raised from 298 to 308 K. Heat supplied to the gas is 500 J. Then, which statement is correct ?
q = W = 500 J, E = 0
q = E = 500 J, W = 0
q = - W = 500 J, E = 0
E = 0, q =W = - 500 J
Standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are -382.64 kJ mol-1 and -145.6 J K mol-1, respectively. Standard Gibb's energy change for the same reaction at 298 K is
-221.1 kJ mol-1
-339.3. kJ mol-1
-439.3 kJ mol-1
-523.2 kJ mol-1
