Thermodynamics practice · Medium

Consider the following properties:

"Temperature, Heat, Molar enthalpy, Internal energy, Density"

The number of intensive and extensive properties are respectively

During an adiabatic expansion a gas obeys $V T^3=$ constant . The gas must be :

Calculate the change in entropy $\left(\Delta_{{r}} {S}^{\circ}\right)$ at $298 \mathrm{~K}$ for the reaction in which urea is formed from ${NH}_3$ and ${CO}_2$

$2N{H_3}\left( {\text{g}} \right) + C{O_2}\left( {\text{g}} \right) \to N{H_2} - \mathop C\limits_{\begin{array}{cccccccccccccccccccc} {||} \\ O \end{array}} - N{H_2}\left( {{\text{aq}}} \right) + {H_2}O\left( \ell \right)$

The standard entropy of ${NH}_2{CONH}_2(\mathrm{aq}), {CO}_2(\mathrm{g}), {NH}_3(\mathrm{g})$ and ${H}_2 {O}(\ell)$ are $174.0, 213.7, 195$ and $75 \mathrm{~JK}^{-1} \mathrm{~mol}^{-1}$ respectively

The heat evolved during the combustion of 112 litre of water gas (mixture of equal volume of ${H_2}$ and CO) is : ${\mathrm{H}_2}\left( \mathrm{g} \right) + \frac{1}{2}{\mathrm{O}_2}\left( \mathrm{g} \right) \to {\mathrm{H}_2}\mathrm{O}\left( \mathrm{g} \right);\Delta H = - 241.8\mathrm{kJ}$ $\mathrm{CO}\left( \mathrm{g} \right) + \frac{1}{2}{\mathrm{O}_2}\left( \mathrm{g} \right) \to \mathrm{C}{\mathrm{O}_2}\left( \mathrm{g} \right);\Delta H = - 283\mathrm{kJ}$

Heat of dissociation of benzene of elements is 5335 kJ/mol. The bond enthalpies of  –C-C-;C=C and –C-H  bonds are 347.3, 615 and 416.2 kJ respectively. Resonance energy of benzene is

A hypothetical reaction, $X\xrightarrow{\,}\,2Y$ proceeds by the following sequence of steps
(i) $\frac{1}{2}X\xrightarrow{\,}\,Z;\,\,\,\,\,\,\,\Delta H = {q_1}$
(ii) $Z\xrightarrow{\,}\,2W;\,\,\,\,\,\,\,\Delta H = {q_2}$
(iii) $W\xrightarrow{\,}\,\frac{1}{2}Y;\,\,\,\,\,\,\,\Delta H = {q_3}$
The value of $\Delta H$ reaction is

The heat of combustion of hydrogen gas at constant pressure and at $23^0 \mathrm{C}$ is $280 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The heat of combustion at constant volume and at $23^0 \mathrm{C}$ will be $\left(\mathrm{R}=8.3143 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}\right)$

The heat of neutralization of $HCl$ by $NaOH$ is – 55.9 KJ/mol. If the heat of neutralization of $HCN$ by $NaOH$ is – 12.1 KJ/mol. The heat of dissociation of $HCN$ is

Statement I : In the following reaction, $CO(g) + 1/2O(g) \to C{O_2}(g);\Delta H = - 68\,\,k\,cal$ and thus, ${\Delta _f}H(C{O_2}) = - 68\,\,k\,cal\,\,mo{l^{ - 1}}$
Statement II : 1 mol of $C{O_2}$ is formed and enthalpy change is the heat of formation of $C{O_2}$

For the process to occur under adiabatic conditions, the correct condition is

What is the entropy change $(in J{K^{ - 1}}mo{l^{ - 1}})$ when one mole of ice is converted into water at 0℃? (The enthalpy change for the conversion of ice to liquid water is 6.0 kJ mol^(-1) at 0℃)

Assertion :- Enthalpy of graphite is lower than that of diamond.

Reason :- Entropy of graphite is greater than that of diamond.

Heat evolved in the reaction ${H_2} + C{l_2} \to 2\,HCl$ is 182 KJ. Bond energies of H-H and $Cl - Cl$ are 430 and 242 KJ/mol respectively. The $H - Cl$ bond energy is

For a spontaneous process, the correct statement is :

For the reactions,

(i) ${H}_2(\mathrm{~g})+{Cl}_2(\mathrm{~g}) \longrightarrow 2 {HCl}(\mathrm{g})+{xkJ}$

(ii) ${H}_2(\mathrm{~g})+{Cl}_2(\mathrm{~g}) \longrightarrow 2 {HCl}(\ell)+{ykJ}$

Which one of the following statement is correct :

When two moles of hydrogen expands isothermally against a constant pressure of 1 atm, at 25℃ from 15 L to 50 L, the work done (in litre atm) will be

The change in entropy, ∆S is positive for an endothermic reaction. If enthalpy charge ∆H occurs at the same temperature T, then the reaction is feasible:

The enthalpy of formation of water from hydrogen and oxygen is - 286 kJ $\mathrm{mo}{\mathrm{l}^{ - 1}}$. The enthalpy of decomposition of water into hydrogen and oxygen is:

The standard molar enthalpies of formation of $\mathrm{IF}_3(\mathrm{g})$ and $\mathrm{IF}_5(\mathrm{g})$ are $-470 \mathrm{~kJ}$ and $-847 \mathrm{~kJ},$ respectively. Valence shell electron-pair repulsion theory predicts that $\mathrm{IF}_5(\mathrm{g})$ is square pyramidal in shape in which all $\mathrm{I}-\mathrm{F}$ bonds are equivalent while $\mathrm{IF}_3(\mathrm{g})$ is T-shaped (based on trigonal-bipyramidal geometry) in which $\mathrm{I}-\mathrm{F}$ bonds are of different lengths. It is observed that the axial $\mathrm{I}-\mathrm{F}$ bonds in $\mathrm{IF}_3$ are equivalent to the $\mathrm{I}-\mathrm{F}$ bonds in $\mathrm{IF}_5.$ Calculate the equatorial $\mathrm{I}-\mathrm{F}$ bond strength in $\mathrm{IF}_3.$ Some other details given are as follows.

$\begin{aligned} & \mathrm{I}_2(\mathrm{s}) \rightarrow \mathrm{I}_2(\mathrm{g}): \Delta H=62 \mathrm{~kJ} \\ & \mathrm{F}_2(\mathrm{g}) \rightarrow 2 \mathrm{~F}(\mathrm{g}): \Delta H=155 \mathrm{~kJ} \\ & \mathrm{I}_2(\mathrm{g}) \rightarrow 2 \mathrm{I}(\mathrm{g}): \Delta H=149 \mathrm{~kJ} \end{aligned}$

The enthalpy of combustion of methane, graphite and dihydrogen at 298 K are –890.3 KJ/mol, –393.5 KJ/mol and –285.8 KJ/mol respectively. Enthalpy of formation of $C{H_4}\left( g \right)$ will be

Assertion : The increase in internal energy $(\Delta E)$ for the vaporization of one mole of water at $1 {~atm}$ and $373 {~K}$ is zero.

Reason : For all isothermal processes, $\Delta E=0$.

Statement I : In the following reaction, $C(s) + {O_2}(g) \to C{O_2}(g);\Delta H = \Delta E - RT$
Statement II : $\Delta H$ is related to $\Delta E$ by equation $\Delta H = \Delta E + \Delta {n_g}RT$

Statement-I : At equilibrium $\Delta {G^0}$ always zero.
Statement-II : At STP active masses of 11.2 L of ${O_2}\left( g \right)$ and 5.6 L of ${N_2}\left( g \right)$ are equal.

Assertion (A): Volume of water in a pond is not a state function.
Reason (R): Volume of water is independent of the route by which water is filled in the pond either by rain or by tubewell or by both.

The heat of neutralisation of a strong acid and a strong alkali is 57.0 kJ $\mathrm{mo}{\mathrm{l}^{ - 1}}$. The heat released when 0.5 mole of $\mathrm{HN}{\mathrm{O}_3}$ solution is mixed with 0.2 mole of KOH is

Heat of neutralisation of strong acid and strong base under $1 {~atm}$ and $25^{\circ} {C}$ is $-13.7\, {kcal}$. If standard Gibbs energy change for dissociation of water to ${H}^{+}$and ${OH}^{-}$ is $-19.14\, {kcal}$, the change in standard entropy for dissociation of water in $cal \,K \,{mol}^{-1}$ is :

Five moles of an ideal gas expand isothermally and reversibly from an initial pressure of $100 \mathrm{~atm}$ to a final pressure of $1 \mathrm{~atm}$ at $27^{\circ} \mathrm{C}.$ The work done by the gas is $(\ln 100=4.6)$

For an ideal monoatomic gas, molar heat capacity at constant volume $\left( {{C_v}} \right)$ is

The van’t Hoff reaction isotherm is:

${\mathrm{H}_2}\left( \mathrm{g} \right) + \frac{1}{2}{\mathrm{O}_2}\left( \mathrm{g} \right) \to {\mathrm{H}_2}\mathrm{O}\left( l \right);\Delta H = - 68\mathrm{kcal}$.The heat change, for the decomposition of 3.6 g of water is :