The bond energy of H—H and Cl-Cl is 430 kJ
mol^-1 and 240 kJ mol^-1 respectively and ΔH_f for HCl is -90 kJ mol^-1. The bond enthalpy of HCl is:

1. 290 $kJ$ $mo{l}^{-1}$

2. 380 $kJ$ $mo{l}^{-1}$

3. 425 $kJ$ $mo{l}^{-1}$

4. 245 $kJ$ $mo{l}^{-1}$

A gas $\left({\mathrm{C}}_{\mathrm{v}, \mathrm{m}}=\frac{5}{2}\mathrm{R}\right)$ behaving ideally was allowed to expand reversibly and adiabatically from 1 litre to 32 litre. It's initial temperature was 327$°$C. The molar enthalpy change (in J/mol) for the process is:

1.  -1125 R

2.  -675

3.  -1575 R

4.  None of these

2 mole of an ideal monoatomic gas undergoes a reversible process for which PV²=C. The gas is expanded from initial volume of 1 L to final volume of 3 L starting from initial temperature of 300 K. Find $△\mathrm{H}$ for the process:

1.  -600 R

2.  -1000 R

3.  -3000 R

4.  None of these

Calculate $△\mathrm{S}$ for 3 mole of a diatomic ideal gas which is heated and compressed from 298 K and 1 bar to 596 K and 4 bar: [Given: C_{v, m} (gas)=$\frac{5}{2}$ R;  ln (2)=0.70;  R=2 cal k^-1 mol^-1]

1.  -14.7 cal K^-1

2.  +14.7 cal K^-1

3.  -6.9 cal K^-1

4.  6.3 cal K^-1

For the hypothetical reaction
                                    ${\mathrm{A}}_2\left(\mathrm{g}\right)+{\mathrm{B}}_2\left(\mathrm{g}\right) \rightleftharpoons 2\mathrm{AB}\left(\mathrm{g}\right)$
${△}_{\mathrm{r}}{\mathrm{G}}^{\circ } \mathrm{and} {△}_{\mathrm{r}}{\mathrm{S}}^{\circ }$ are 20 kJ/mol and -20 JK^-1 mol^-1 respectively at 200 K.
If ${△}_{\mathrm{r}}{\mathrm{C}}_{\mathrm{P}}$ is 20 JK^-1 mol^-1 then ${△}_{\mathrm{r}}{\mathrm{H}}^{\circ }$ at 400 K is:

1.  20 kJ/mol

2.  7.98 kJ/mol

3.  28 kJ/mol

4.  None of these

Calculate ${△}_{\mathrm{f}}\mathrm{H}°$ (in kJ/mol) for ${\mathrm{Cr}}_2{\mathrm{O}}_3$ from the ${△}_{\mathrm{r}}\mathrm{G}°$ and the $\mathrm{S}°$ values provided at 27$°$C

\(\begin{array}{ll} 4 C r(s)+3 O_2(g) \rightarrow 2 C r_2 O_3(s), \\ \Delta_r G^{\circ}=-2093.4 k J / m o l \\ S^{\circ}(\mathrm{J} / / \mathrm{K} \mathrm{~mol}): S^{\circ}(C r, s)=24, \\ S^{\circ}\left(O_2, g\right)=205, \quad S^{\circ}\left(C r_2 O_3, s\right)=81 \end{array}\)

1.  -2258.1 kJ/mol
2.  -1129.05 kJ/mol
3.  -964.35 kJ/mol
4.  None of the above

Boron can undergo the following reactions with the given enthalpy changes: 2B(s)

$2\mathrm{B}\left(\mathrm{s}\right) + \frac{3}{2}{\mathrm{O}}_2 \to {\mathrm{B}}_2{\mathrm{O}}_2\left(\mathrm{s}\right); ∆\mathrm{H} = -1260 \mathrm{kJ}$
$2\mathrm{B}\left(\mathrm{s}\right) + 3{\mathrm{H}}_2 \to {\mathrm{B}}_2{\mathrm{H}}_6\left(\mathrm{s}\right); ∆\mathrm{H} = 30 \mathrm{kJ}$

Assume no other reactions are occurring. If in a container (operating at constant pressure) which is isolated from the surrounding, a mixture of H2(gas) and ${\mathrm{O}}_2$ (gas) is passed over excess of B(s), then calculate the molar ratio (${\mathrm{O}}_2;{\mathrm{H}}_2$) so that the temperature of the container does not change :

1. 15:3

2. 42:1

3. 1:42

4. 1:84

Consider the reaction at 300 K ${\mathrm{C}}_6{\mathrm{H}}_6\left(\mathrm{l}\right) + \frac{15}{2}{\mathrm{O}}_2\left(\mathrm{g}\right) \to 6{\mathrm{CO}}_2\left(\mathrm{g}\right) +3{\mathrm{H}}_2\mathrm{O}\left(\mathrm{I}\right); (∆\mathrm{H}) = -3271 \mathrm{kJ}$. What is AU for the combustion of 1.5 moles of benzene at 27°C

1. -3267.25 kJ

2. -4900.88 kJ

3. -4906.5 kJ

4. -3274.75 kJ

A gas expands against a variable pressure given by P = 20/V (where P in atm and V in L). During expansion from the volume of 1 liter to 10 liters, the gas undergoes a change in internal energy of 400 J. How much heat is absorbed by the gas during expansion?

1. 46 J

2. 4660 J

3. 5065.8 J

4. 4260 J

An ideal gas is taken around the cycle ABCA as shown in P-V diagram. The network done during the cycle is equal to :

1. 12 ${\mathrm{P}}_1{\mathrm{V}}_1$

2. 6 ${\mathrm{P}}_1{\mathrm{V}}_1$

3. 5 ${\mathrm{P}}_1{\mathrm{V}}_1$

4. ${\mathrm{P}}_1{\mathrm{V}}_1$