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5
MCQ (Single Correct Answer)

During complete combustion of one mole of butane, 2658 kJ of heat is released. The thermochemical reaction for above change is

A
$2 \mathrm{C}_4 \mathrm{H}_{10}(\mathrm{~g})+13 \mathrm{O}_2(\mathrm{~g}) \rightarrow 8 \mathrm{CO}_2(\mathrm{~g})+10 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) ; \Delta_{\mathrm{c}} \mathrm{H}=-2658.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$
B
$\mathrm{C}_4 \mathrm{H}_{10}(\mathrm{~g})+\frac{13}{2} \mathrm{O}_2(\mathrm{~g}) \rightarrow 4 \mathrm{CO}_2(\mathrm{~g})+5 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) ; \Delta_{\mathrm{C}} \mathrm{H}=-1329.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$
C
$\mathrm{C}_4 \mathrm{H}_{10}(\mathrm{~g})+\frac{13}{2} \mathrm{O}_2(\mathrm{~g}) \rightarrow 4 \mathrm{CO}_2(\mathrm{~g})+5 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) ; \Delta_{\mathrm{C}} \mathrm{H}=-2658.0 \mathrm{~kJ} \mathrm{~mol}{ }^{-1}$
D
$\mathrm{C}_4 \mathrm{H}_{10}(\mathrm{~g})+\frac{13}{2} \mathrm{O}_2(\mathrm{~g}) \rightarrow 4 \mathrm{CO}_2(\mathrm{~g})+5 \mathrm{H}_2 \mathrm{O}(l) ; \Delta_{\mathrm{c}} H=+2658.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$
6
MCQ (Single Correct Answer)

$\Delta_f U^{\mathrm{s}}$ of formation of $\mathrm{CH}_4(\mathrm{~g})$ at certain temperature is $-393 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The value of $\Delta_f H^{\mathrm{s}}$ is

A
zero
B
$>\Delta_f U^{\mathrm{s}}$
C
$<\Delta_f U^{\mathrm{s}}$
D
equal to $\Delta_f U^{\mathrm{s}}$
7
MCQ (Single Correct Answer)

In an adiabatic process, no transfer of heat takes place between system and surroundings. Choose the correct option for free expansion of an ideal gas under adiabatic condition from the following.

A
$q=0, \Delta T \neq 0, W=0$
B
$q \neq 0, \Delta T=0, W=0$
C
$q=0, \Delta T=0, W=0$
D
$q=0, \Delta T<0, W \neq 0$
8
MCQ (Single Correct Answer)

The pressure-volume work for an ideal gas can be calculated by using the expression $W=-\int_\limits{V_i}^{V_f} p_{e x} d V$. The work can also be calculated from the $p V$-plot by using the area under the curve within the specified limits. When an ideal gas is compressed (a) reversibly or (b) irreversibly from volume $V_i$ to $V_f$. Choose the correct option.

A
$W$ (reversible) $=W$ (irreversible)
B
$W$ (reversible) $< W$ (irreversible)
C
$W$ (reversible) $=W$ (irreversible)
D
$W$ (reversible) $=W$ (irreversible) $+p_{\mathrm{ex}} \cdot \Delta V$
9
MCQ (Single Correct Answer)

The entropy change can be calculated by using the expression $\Delta S=\frac{q_{\text {rev }}}{T} \cdot$ When water freezes in a glass beaker, choose the correct statement amongst the following.

A
$\Delta S$ (system) decreases but $\Delta S$ (surroundings) remains the same
B
$\Delta S$ (system) increases but $\Delta S$ (surroundings) decreases
C
$\Delta S$ (system) decreases but $\Delta S$ (surroundings) increases
D
$\Delta S$ (system) decreases but $\Delta S$ (surroundings) also decreases
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