For the reaction,
C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(l) at constant temperature, H - E is
+ 3RT
- RT
+ RT
- 3RT
Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction ?
Exothermic and decreasing disorder
Endothermic and increasing disorder
Exothermic and increasing disorder
Endothermic and decreasing disorder
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
Bond dissociation enthalpy of H2,CI2 and HCI are 434, 242 and 431 kJ mol-1 respectively. Enthalpy of formation of HCI is
93 kJ mol-1
-245 kJ mol-1
-93 kJ mol-1
245 kJ mol-1
During isothermal expansion of an ideal gas, its
internal energy increases
enthalpy decreases
enthalpy remains unaffected
enthalpy reduces to zero
Change in enthalpy for reaction
2H2O2(l) → 2H2O(l) + O2 (g)
if heat of formation of H2O2(l) and H2O(l) are -188 and -286 kJ/mol respectively is,
-196 kJ/mol
+ 196 kJ/mol
+ 948 kJ/mol
-948 kJ/mol
The absolute enthalpy of neutralisation of the reaction
MgO(s) + 2HCI(aq) → MgCI2(aq) + H2O(l) will be
less than -57.33 kJ mol-1
-57.33 kJ mol-1
greater than -57.33 kJ mol-1
57.33 kJ mol-1
In an endothermic reaction, the value of H is
zero
positive
negative
constant
Unit of entropy is
JK-1 mol-1
J mol-1
J-1 K-1 mol-1
JK mol-1
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
