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


1. $∆S_{system}+∆S_{surroundings}>0$

2. $∆S_{system}-∆S_{surroundings}>0$

3. $∆S_{system}>\mathrm{0\; only}$

4. $∆S_{s\mathrm{urroundings}}>\mathrm{0\; only}$

For which of the following processes will the entropy increase? 

1. Reaction of magnesium with oxygen to form magnesium oxide

2. Reaction of nitrogen and hydrogen to form ammonia 

3. Sublimation of dry ice

4. Condensation of steam 

Which of the following is the correct first law thermodynamics equation?

(1) $U=∆Q-W$
$$

(2) $∆W=∆U+∆Q$
$$

(3) $∆U=∆W+∆Q$

(4) None of these 

Which of the following conditions result in a spontaneous reaction?

1. Exothermic and increasing disorder

2. Exothermic and decreasing disorder

3. Endothermic and increasing disorder

4. Endothermic and decreasing disorder

Assume each reaction is carried out in an open container. For which of the following reactions will $∆\mathrm{H\; be\; equal\; to }∆\mathrm{U}?$

1. ${\mathrm{PCl}}_3\left(\mathrm{g}\right)$ $\to {\mathrm{PCl}}_3\left(\mathrm{g}\right)$ $+{\mathrm{Cl}}_2\left(\mathrm{g}\right)$ $$

2. $2\mathrm{CO}\left(\mathrm{g}\right)$ $+{\mathrm{O}}_2\left(\mathrm{g}\right)$ $\to 2{\mathrm{CO}}_2\left(\mathrm{g}\right)$ $$

3. ${\mathrm{H}}_2\left(\mathrm{g}\right)$ $+{\mathrm{Br}}_2\left(\mathrm{g}\right)$ $\to 2\mathrm{HBr}\left(\mathrm{g}\right)$

4. $\mathrm{C}\left(\mathrm{s}\right)$ $+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$ $\to 2{\mathrm{H}}_2\left(\mathrm{g}\right)$ $+{\mathrm{CO}}_2\left(\mathrm{g}\right)\hspace{0.17em}$

ldentify the correct statement regarding entropy:

1. At absolute zero temperature, entropy of a perfectly crystalline

     substance is +ve.

2. At absolute zero temperature, entropy of a perfectly crystalline

     substance is taken to be zero 

3. At absolute zero temperature, entropy of all crystalline substances

     in taken to be 0.

4. At 0$°$ C entropy of a perfectly crystalline substance is taken to

      be 0.

The reaction that has a value of $∆S°$ greater than zero among the following is-

\( \begin{align} & {{1}{.}\;{CaO}\left({s}\right){+}{CO}_{2}\rightarrow{CaCO}_{3}\left({s}\right)}\\ & {{2}{.}\;{NaCl}\left({aq}\right)\rightarrow{NaCl}\left({s}\right)}\\ & {{3}{.}\;{NaNO}_{3}\left({s}\right)\rightarrow{Na}^{{+}}\left({aq}\right){+}{NO}_{3}^{{-}}\left({aq}\right)}\\ & {{4}{.}\;{N}_{2}\left({g}\right){+}{3}{H}_{2}\left({g}\right)\rightarrow{2}{NH}_{3}\left({g}\right)} \end{align}\)

The net work done for an ideal gas is given as 

1. $-$3PV

2. 3PV

3. PV

4. Zero

Which of the following statements is correct for a spontaneous process?

1. The entropy of the system always increases.

2. The free energy of the system always increases. 

3. The total entropy change is always negative. 

4. The total entropy change is always positive.

Which one of the following has the maximum entropy of vaporization?

(Assuming all are in the liquid phase)

1. Water  

2. Toluene 

3. Diethyl ether 

4. Acetone