Thermodynamics

The values of \(\Delta\)H and \(\Delta\)S for the reaction,
C(graphite) + CO2(g) \(\to\)  2CO(g)
are 170 kJ and 170 J K\(-\)1, respectively. This reaction will be spontaneous at

From the following bond energies :
H \(-\) H bond energy   : 431.37 kJ mol\(-\)1
C \(=\) C bond energy   : 606.10 kJ mol\(-\)1
C \(-\) C bond energy   : 336.49 kJ mol\(-\)1
C \(-\) H bond energy   : 410.50 kJ mol\(-\)1
Enthalpy for the rea...

For the gas phase reaction,
PCl5(g)  \(\rightleftharpoons\) PCl3(g) + Cl2(g)
which of the following conditions are correct ?

Bond dissociation enthalpy of H2, Cl2 and HCl are 434, 242 and 431 kJ mol\(-\)1 respectively. Enthalpy of formation of HCl is

Which of the following are not state functions ?
(I) q + w     (II) q
(III) w        (IV) H \(-\) TS

Given that bond energies of H \(-\) H and Cl \(-\) Cl are 430 kJ mol\(-\)1 and 240 kJ mol\(-\)1 respectively and \(\Delta\)Hf for HCl is \(-\) 90 kJ mol\(-\)1, bond enthalpy of HCl is

Consider the following reactions :
(i) H+(aq) + OH\(-\)(aq) = H2O(l),  \(\Delta\)H = \(-\) X1 kJ mol\(-\)1
(ii) H2(g) + 1/2O2(g) = H2O(l),   \(\Delta\)H = \(-\) X2 kJ mol\(-\)1
(iii) CO2(g) + H2(g) = CO(g) + H2O(l),  \(\Delta\)H = $$-$...

Assume each reaction is carried out in an open container. For which reaction will \(\Delta\)H = \(\Delta\)E ?

Identify the correct statement for change of Gibb's energy for a system (\(\Delta\)Gsystem) at constant temperature and pressure.

The enthalpy of hydrogenation of cyclohexene is is \(-\) 119.5 kJ mol\(-\)1. If resonance energy of benzene is \(-\) 150.4 kJ mol\(-\)1, its enthalpy of hydrogenation would be

The enthalpy and entropy change for the reaction:
Br2(l) + Cl2(g) \(\to\) 2BrCl(g)
are 30 kJ mol\(-\)1 and 105 J K\(-\)1 mol\(-\)1 respectively.
The temperature at which the reaction will be in equilibrium is

The absolute enthalpy of neutralisation of the reaction :
Mg(O)(s) + 2HCl(aq) \(\to\) MgCl2(aq) + H2O(l) will be

A reaction occurs spontaneously if

Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction ?

Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is

The work done during the expansion of a gas from a volume of 4 dm3 to 6 dm3 against a constant external pressure of 3 atm is (1 L atm = 101.32 J)

If the bond energies of H \(-\) H, Br \(-\) Br, and H \(-\) Br are 433, 192 and 364 kJ mol\(-\)1 respectively, the \(\Delta\)Ho for the reaction H2(g) + Br2(g) \(\to\) 2HBr(g) is

Standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are \(-\) 382.64 kJ mol\(-\)1 and \(-\) 145.6 kJ mol\(-\)1, respectively. Standard Gibb's energy change for the same reaction at 298 K is

The molar heat capacity of water at constant pressure, C, is 75 J K\(-\)1 mol\(-\)1. When 1.0 kJ of heat is supplied to 100 g of water which is free to expand, the increase in temperature of water is

Formation of solution from two components can be considered as
(i) Pure solvent \(\to\) separated solvent molecules, \(\Delta\)H1
(ii) Pure solute \(\to\) separated solute molecules, \(\Delta\)H2
(iii) Separated solvent and solute mo...

For the reaction,
C3H8(g) + 5O2(g) \(\to\) 3CO2(g) + 4H2O(l)
at constant temperature, \(\Delta\)H \(-\) \(\Delta\)E is

The densities of graphite and diamond at 298 K are 2.25 and 3.31 g cm\(-\)3, respectively. If the standard free energy difference \(\left( {\Delta {G^o}} \right)\) is equal to 1895 J mol\(-\)1, the pressure at which graphite will be transfo...

What is the entropy change (in J K\(-\)1 mol\(-\)1) when one mole of ice is converted into water at 0oC? (The enthalpy change for the conversion of ice to liquid water is 6.0 kJ mol\(-\)1 at 0oC).

For which one of the following equations is \(\Delta\)Horeact equal to \(\Delta\)Hof for the product ?

In a closed insulated container a liquid is stirred with a paddle to increase the temperature which of the following is true ?

2 mole of ideal gas at 27oC temperature is expanded reversibly from 2 lit. to 20 lit. Find entropy change. (R = 2 cal/mol K)

Heat of combustion \(\Delta\)Ho for C(s), H2(g) and CH4(g) are \(-\) 94, \(-\) 68 and \(-\)213 kcal/mol, then \(\Delta\)Ho for C(s) + 2H2(g) \(\to\) CH4(g) is

Which reaction is not feasible?

Unit of entropy is

Change in enthalpy for reaction,
2H2O2(l) \(\to\) 2H2O(l) + O2(g)
if heat of formation of H2O2(l) and H2O(l) are \(-\)188 and - 286 kJ/mol respectively, is

When 1 mol of 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 ?

Enthalpy of CH4 + \({1 \over 2}\) O2 \(\to\) CH3OH is negative. If enthalpy of combustion of CH4 and CH3OH are x and y respectively. Then which relation is correct?

PbO2  \(\to\) PbO; \(\Delta\)G298 < 0
SnO2 \(\to\) SnO;  \(\Delta\)G298 > 0
Most probable oxidation state of Pb and Sn will be

For the reaction,
C2H5OH(l) + 3O2(g) \(\to\) 2CO2(g) + 3H2O(l)
which one is true

2Zn + O2 \(\to\) 2ZnO;  \(\Delta\)Go = \(-\) 616 J
2Zn + S2 \(\to\) 2ZnS;  \(\Delta\)Go = \(-\) 293 J
S2 + 2O2 \(\to\) 2SO2;   \(\Delta\)Go = \(-\)408 J
\(\Delta\)Go for the following reaction
2ZnS + 3O2 \(\to\)  2ZnO + 2SO2 is...

The entropy change in the fusion of one mole of a
solid melting at 27oC (latent heat of fusion is 2930 J
mol–1) is :