The enthalpy of combustion for the H₂, cyclohexene and cyclohexane are -241, -3800 and -3920 kJ mol^-1 respectively. Heat of hydrogenation of cyclohexene is

• 121 kJ mol^-1

• -121 kJ mol^-1

• 242 kJ mol^-1

• -242 kJ mol^-1

If  H_f (H₂O) is -286.20 kJ mol^-1, then  H${}_{\mathrm{f}}^{°}$  (OH^-) is

• -228.88 kJ mol^-1

• +228.88 kJ mol^-1

• -343.52 kJ mol^-1

• +343.52 kJ mol^-1

1 mole of gas occupying 3 L volume is expanded against a constant external pressure of 1 atm to a volume of 15 L. The work done by a system is equal to

• -1.215 × 10³ J

• -12.15 × 10³ J

• +1.215 × 10³ J

• +12.15 × 10³ J

Which one of the following is not a state function?

• Internal energy

• Work

• Entropy

• Free energy

Given that N₂(g) + 3H₂(g) → 2NH₃(g): Δ_rH° =-92kJ, the standard molar enthalpy of formation in kJ mol^-1 of NH₃(g) is 

• -92

• +46

• +92

• -46

In view of ${∆}_{\mathrm{r}}\mathrm{G}°$ for the following reactions

PbO₂ + Pb → 2PbO, ${∆}_{\mathrm{r}}\mathrm{G}°\mathrm{r}$

SnO₂ + Sn → 2SnO, ${∆}_{\mathrm{r}}\mathrm{G}°\mathrm{r}$

Which oxidation state is more characteristic for lead and tin?

• For lead +2, for tin +2

• For lead +4, for tin +4

• For lead +2, for tin +4

• For lead +4, for tin +2

247.

The enthalpy of the formation of CO₂ and H₂O are -395 kJ and -285 kJ respectively and the enthalpy of combustion of acetic acid is 869 kJ. The enthalpy of formation of acetic acid is

• 340 kJ

• 420 kJ

• 491 kJ

• 235 kJ

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

• $∆{\mathrm{S}}_{\mathrm{system}} >0 \mathrm{only}$

• $∆{\mathrm{S}}_{\mathrm{surrounding}} > 0$

• $\left(∆{\mathrm{S}}_{\mathrm{system}} + ∆{\mathrm{S}}_{\mathrm{surrounding}}\right) > 0$

• $(∆{\mathrm{S}}_{\mathrm{system}} - ∆{\mathrm{S}}_{\mathrm{surrounding}}) > 0$

Standard enthalpy (heat) of formation of liquid water at 25°C is around

 H₂(g) + $\frac{1}{2}$O₂(g) → H₂O (l)

• -237 kJ/mol

• 237 kJ/mol

• - 286 kJ/mol

• 286 kJ/mol

Given ΔH_f° for CO₂(g) , CO(g) and H₂O(g) are -393.5, -110.5 and -241.8 kJ mol^-1, respectively. The ΔH_f° [in kJ mol^-1] for the reaction

CO₂(g) + H₂(g) → CO(g) + H₂O (g) is

• 524.1

• -262.5

• -417

• 412