A reaction occurs spontaneously if:

1. T∆S > ∆H and ∆H is +ve and ∆S are –ve

2. T∆S = ∆H and both ∆H and ∆S are +ve

3. T∆S < ∆H and both ∆H and ∆S are +ve

4. T∆S > ∆H and both ∆H and ∆S are +ve

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

1. Endothermic and decreasing disorder

2. Exothermic and increasing disorder

3. Endothermic and increasing disorder

4. Exothermic and decreasing disorder

Identify the correct statement regarding entropy:

One mole of an ideal gas at 300 K is expanded isothermally from an initial volume of 1 litre to 10 litres. The ∆E for this process is:
(R = 2 cal. $mo{l}^{-1}{K}^{-1}$)

If the bond energies of H–H, Br – Br, and H –Br are 433, 192, and 364 kJ mol^–1 respectively, the ∆Hº for the reaction H₂(g) + Br₂(g) → 2HBr(g) will be:

1. +103 kJ

2. +261kJ

3. –103 kJ

4. –261 kJ 

Which of the following statements are true for a cyclic process?

1.  a, b
2.  b, c
3.  c, d
4.  a, d

If a system is expanded under adiabatic process, then:

1.  Temperature increases
2.  ∆E decreases
3.  ∆E increases
4.  None of the above

Which of the following statements is true for a reaction where all the reactants and products are in the liquid phase?

1. ∆H = ∆E
2. ∆H = ∆W
3. ∆H > ∆E
4. None of the above

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

1. ${\mathrm{\Delta S}}_{\mathrm{system<mspace\; width="1em"></mspace>}}-{\mathrm{\Delta S}}_{\mathrm{surrounding<mspace\; width="1em"></mspace>}}>0$

2. ${\mathrm{\Delta S}}_{\mathrm{system<mspace\; width="1em"></mspace>}}>0\mathrm{<mspace\; width="1em"></mspace>only<mspace\; width="1em"></mspace>}$

3. ${\mathrm{\Delta S}}_{\mathrm{surroundings<mspace\; width="1em"></mspace>}}>\mathrm{0}$ $\mathrm{only}$

4. ${\mathrm{\Delta S}}_{\mathrm{system<mspace\; width="1em"></mspace>}}+{\mathrm{\Delta S}}_{\mathrm{surrounding<mspace\; width="1em"></mspace>}}>0$

The standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are –382.64 kJ mol^–1 and –145.6 JK^–1 mol^–1, respectively. Standard Gibbs energy change for the same reaction at 298 K is:

1. –339.3 kJ mol^–1

2. – 439.3 kJ mol^–1

3. –523.2 kJ mol^–1

4. –221.1 kJ mol^–1