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 crystaline

     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 crystaline sustances

     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

For a spontaneous process, the correct statement is 

1. Entropy of the system always increases

2. Free energy of the system always increases 

3. Total entropy change is always negative 

4. Total entropy change is always positive

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

1. water (l) 

2. toluene (l)

3. diethyl ether (l) 

4. acetone (l) 

Which of the following is not an endothermic reaction?

1. Combustion of methane

2. Decomposition of water

3. Dehydrogenation of ethane or ethylene

4. Conversion of graphite to diamond

Which of the following statements is false?

1. Work is a state function.

2. Temperature is a state function.

3. Density is a state function.

4. Entropy is state function.