Thermodynamics

\(\text { Consider the reversible processes for } 1.0 \mathrm{~mol} \text { of an ideal gas as shown in the figure. }\)

$w_1, w_2, w_3$ and $w_4$ represent work done (in calories) in the processes $1,2,3$ and 4 , respectively; $\Delta U_...

A protein undergoes reversible thermal denaturation from its initial state $\mathbf{N}$ to denatured state $\mathbf{D}$ according to $\mathbf{N} \rightleftharpoons \mathbf{D}$. At $60^{\circ} \mathrm{C}$, the concentrations of both $\mathbf...

Two moles of an ideal gas undergo free expansion from 10 L to 100 L at 300 K . The values of $\Delta \mathrm{S}_{\text {system }}$ and $\Delta \mathrm{S}_{\text {surroundings }}$ are
( $R$ is universal gas constant)

At a certain temperature, $\mathrm{T}(\mathrm{K})$, during a process, 500 J is absorbed by the system and work of 200 J is done by the system. Then change in internal energy of the system is :

Consider the following reaction :
$$ \begin{aligned} & 2 \mathrm{~A}(\mathrm{~g})+\mathrm{B}(\mathrm{~g}) \rightarrow 2 \mathrm{D}(\mathrm{~g}) \\ & \Delta \mathrm{U}^{\ominus}=-10 \mathrm{~kJ} \mathrm{~mol}^{-1} \text { and } \Delta \mathr...

$\mathrm{C}(\mathrm{s})+2 \mathrm{H}_2(\mathrm{~g}) \rightarrow \mathrm{CH}_4(\mathrm{~g}) ; \Delta \mathrm{H}=-74.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$. Which of the following diagrams gives an accurate representation of the above reaction? [...

The standard heat of formation, in $\mathrm{kcal} / \mathrm{mol}$ of $\mathrm{Ba}^{2+}$ is :
[Given : standard heat of formation of $\mathrm{SO}_4^{2-}$ ion $(\mathrm{aq})=-216 \mathrm{kcal} / \mathrm{mol}$, standard heat of crystallisation...

For the following reaction at \(300 \mathrm{~K}\)
\(\mathrm{A}_2(\mathrm{~g})+3 \mathrm{~B}_2(\mathrm{~g}) \rightarrow 2 \mathrm{AB}_3(\mathrm{~g})\)
the enthalpy change is \(+15 \mathrm{~kJ}\), then the internal energy change is :

For an endothermic reaction:
(A) \(\mathrm{q}_{\mathrm{p}}\) is negative.
(B) \(\Delta_{\mathrm{r}} \mathrm{H}\) is positive.
(C) \(\Delta_r \mathrm{H}\) is negative.
(D) \(\mathrm{q}_{\mathrm{p}}\) is positive.
Choose the correct answer fr...

Choose the correct statement for the work done in the expansion and heat absorbed or released when
5 litres of an ideal gas at 10 atmospheric pressure isothermally expands into vacuum until volume is
15 litres :

The work done during reversible isothermal expansion of one mole of hydrogen gas at \(25^{\circ} \mathrm{C}\) from pressure of 20 atmosphere to 10 atmosphere is (Given \(\mathrm{R}=2.0 \mathrm{~cal} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\))

Match List I with List II.

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In which of the following processes entropy increases?
A. A liquid evaporates to vapour.
B. Temperature of a crystalline solid lowered from \(130 \mathrm{~K}\) to \(0 \mathrm{~K}\).
C. $$2 \mathrm{NaHCO}_{3(\mathrm{~s})} \rightarrow \mathrm...

Consider the following reaction :-
\(2 \mathrm{H}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \rightarrow 2 \mathrm{H}_2 \mathrm{O}(\mathrm{g}) \Delta_{\mathrm{r}} \mathrm{H}^{\circ}=-483.64 \mathrm{~kJ} \text {. }\)
What is the enthalpy chang...

Which amongst the following options is the correct relation between change in enthalpy and change in internal energy?

The equilibrium concentrations of the species in the reaction \(\mathrm{A}+\mathrm{B} \rightleftharpoons \mathrm{C}+\mathrm{D}\) are \(2,3,10\) and \(6 \mathrm{~mol}\) \(\mathrm{L}^{-1}\), respectively at $$300 \mathrm{~K} . \Delta \mathrm{...

A vessel contains 3.2 g of dioxygen gas at STP (273.15 K and 1 atm pressure). The gas is now transferred to another vessel at constant temperature, where pressure becomes one third of the original pressure. The volume of new vessel in L is ...

One mole of an ideal gas at 300 K is expanded isothermally from 1 L to 10 L volume. \(\Delta\)U for this process is :
(Use R = 8.314 J k\(-\)1 mol\(-\)1)

Which of the following p-V curve represents maximum work done?

For irreversible expansion of an ideal gas under isothermal condition, the correct option is :

Which one among the following is the correct option for right relationship between CP and CV for one mole of ideal gas?

The correct option for free expansion of an ideal gas under adiabatic condition is :

Hydrolysis of sucrose is given by the following reaction.Sucrose + H2O ⇌
Glucose + FructoseIf the equilibrium constant (Kc) is 2 \(\times\) 1013 at 800 K, the value of \(\Delta r{G^\Theta }\)
at the same temperature will be :

For the reaction, 2Cl(g) \(\to\) Cl2(g), the correct option is :

Under isothermal condition, a gas at 300 K expands from 0.1 L to 0.25 L against a constant external pressure
of 2 bar. The work done by the gas is [Given that 1 L bar = 100 J]

In which case change in entropy is negative?

The bond dissociation energies of X2
, Y2
and
XY are in the ratio of 1 : 0.5 : 1. \(\Delta\)H for the
formation of XY is –200 kJ mol–1. The bond
dissociation energy of X2
will be

A gas is allowed to expand in a well insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy \(\Delta\)U of the gas in joules will be

For a given reaction, \(\Delta\)H = 35.5 kJ mol\(-\)1 and \(\Delta\)S = 83.6 J K\(-\)1 mol\(-\)1. The reaction is spontaneous at (Assume that \(\Delta\)H and \(\Delta\)S do not vary with temperature.)

For a sample of perfect gas when its pressure is changed isothermally from pi to pf, the entropy change is given by

The correct thermodynamic conditions for the spontaneous reaction at all temperatures is

The heat of combination of carbon to CO2 is \(-\)393.5 kJ/mol. The heat released upon formation of 35.2 g of CO2 from carbon and oxygen gas is

Which of the following statements is correct for the spontaneous adsorption of a gas?

For the reaction, \({X_2}{O_{4\left( l \right)}}\,\, \to \,\,2X{O_{2(g)}}\)
\(\Delta\)U = 2.1 kcal, \(\Delta\)S = 20 cal K\(-\)1 at 300 K
Hence, G is

When 5 litres of a gas mixture of methane and propane is perfectly combusted at 0oC and 1 atmosphere, 16 litres of oxygen at the same temperature and pressure is consumed, The amount of heat released from this combustion in kJ (\(\Delta\)H...

Three thermochemical equations are given below
(i)  C(graphite) + O2(g) \(\to\) CO2(g); \(\Delta\)rHo = x kJ mol\(-\)1
(ii)  C(graphite) + \({1 \over 2}\)O2(g) \(\to\) CO(g); \(\Delta\)rHo = y kJ mol\(-\)1
(iii)  CO(g) + $${1 \over 2...

A reaction having equal energies of activation for forward and reverse reactions has

In which of the following reactions, standard reaction entropy change (\(\Delta\)So) is positive and standard Gibb's energy change (\(\Delta\)Go) decreases sharply with increasing temperature ?

The enthalpy of fusion of water is 1.435 kcal/mol. The molar entropy change for the melting of ice at 0oC is

Standard enthalpy of vaporisation \(\Delta\)vapHo for water at 100oC is 40.66 kJ mol\(-\)1. The internal energy of vaporisation of water at 100oC (in kJ mol\(-\)1) is

If the enthalpy change for the transition of liquid water to steam is 30 kJ mol\(-\)1 at 27oC, the entropy change for the process would be

Enthalpy change for the reaction,
4H(g)  \(\to\)  2H2(g) is \(-\)869.6 kJ
The dissociation energy of H \(-\) H bond is

Which of the following is correct option for free expansion of an ideal gas under adiabatic condition ?

Consider the following processes :

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For an endothermic reaction, energy of activation is Ea and enthalpy of reaction is \(\Delta\)H (both of these in kJ/mol). Minimum value of Ea will be

Standard entropies of X2, Y2 and XY3 are 60, 40 and 50 J K\(-\)1 mol\(-\)1 respectively. For the reaction
1/2X2 + 3/2Y2 \(\rightleftharpoons\) XY3, \(\Delta\)H = \(-\) 30 kJ,
to be at equilibrium, the temperature should be

For vaporization of water at 1 atmospheric pressure, the values of \(\Delta\)H and \(\Delta\)S are 40.63 kJ mol\(-\)1 and 108.8 J K\(-\)1 mol\(-\)1, respectively. The temperature when Gibb's energy change (\(\Delta\)G) for this transform...

The following two reactions are known
Fe2O3(s) + 3CO(g) \(\to\) 2Fe(s) + 3CO2(g);
\(\Delta\)H = \(-\) 26.8 kJ
FeO(s) + CO(g) \(\to\)  Fe(s) + CO2(g); \(\Delta\)H = \(-\) 16.5 kJ
The value of \(\Delta\)H for the following reaction...

Match List I (Equations) with List II (Type of processes) and select the correct option.

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Three moles of an ideal gas expanded spontaneously into vacuum. The work done will be