1. The favourable conditions for a spontaneous reaction are
a) $T\triangle S>\triangle H,\triangle H=+Ve,\triangle S=+Ve$
b) $T\triangle S<\triangle H,\triangle H=+Ve,\triangle S=-Ve$
c) $T\triangle S=\triangle H,\triangle H=-Ve,\triangle S=-Ve$
d) $T\triangle S=\triangle H,\triangle H=+Ve,\triangle S=+Ve$

Explanation: $\triangle$G = $\triangle$H -T$\triangle$S, $\triangle$H + ve, $\triangle$S is + ve; T$\triangle$S > $\triangle$H for spontaneous process. It will make $\triangle$G, –ve

2. Identify the correct statement regarding entropy
a) At absolute zero temperature, entropy of a perfectly crystalline substance is taken to be zero
b) At absolute zero temperature, the entropy of a perfectly crystalline substance is positive
c) Absolute entropy of a substance cannot be determined
d) At 0°C, the entropy of a perfectly crystalline substance is taken to be zero

Explanation: Third law of Thermodynamics

3. For which of the following process, $\triangle S$   is negative?
a) $H_{2}\left(g\right)\rightarrow 2H\left(g\right)$
b) $N_{2}\left(g\right)\left(1atm\right)\rightarrow N_{2}\left(g\right)\left(8atm\right)$
c) $2SO_{3}\left(g\right)\rightarrow 2SO_{2}\left(g\right)+O_{2}\left(g\right)$
d) $C_{\left(diamond\right)}\rightarrow C_{\left(graphite\right)}$

Explanation: High pressure reduces volume, decreases entropy, hence $\triangle$S negative.

4. According to second law of thermodynamics a process (reaction) is spontaneous if during the process
a) $\triangle S_{universe}>0$
b) $\triangle S_{universe}=0$
c) $\triangle S_{system}>0$
d) $\triangle S_{universe}=\triangle S_{system}$

Explanation: For spontaneous process, $\triangle$Stotal is +ve

5. The law formulated by Nernst is
a) first law of thermodynamics
b) second law of thermodynamics
c) third law of thermodynamics
d) Both (a) and (b)

Explanation: Third law of thermodynamics is due to Nernst

6. If 900 J/g of heat is exchanged at boiling point of water, then what is increase in entropy?
a) 43.4 J/mole
b) 87.2 J/mole
c) 900 J/mole
d) Zero

Explanation:

7. Given the following entropy values $\left( JK^{-1}mol^{-1}\right)$   at 298 K and 1 atm : $H_{2} \left(g\right): 130.6, Cl_{2}\left(g\right): 223.0$      and HCl(g): 186.7. The entropy change $\left( JK^{-1}mol^{-1}\right)$  for the reaction
$H_{2}\left(g\right)+Cl_{2}\left(g\right)\rightarrow 2HCl\left(g\right)$
a) +540.3
b) 727.0
c) –166.9
d) 19.8

Explanation:

8. Entropy change involved in the conversion of 1 mole of liquid water at 373 K to vapour at the same temperature will be $\left(\triangle H_{vap.}=2.257kJ /g\right)$
a) 0.119 kJ
b) 0.109 kJ
c) 0.129 kJ
d) 0.12 kJ

Explanation:

9.Which relation is correct ?
a) $\triangle G=\triangle H -T\triangle S$
b) $\triangle G=\triangle H +T\triangle S$
c) $\triangle G=T\triangle S-\triangle H$
d) $\triangle G=\triangle H- SdT$

Explanation: $\triangle$G=$\triangle$H-T$\triangle$S
Explanation: At equilibrium, $\triangle$G =0