Chemical Thermodynamics — JEE Advanced PYQs

An ideal gas (0.5 mol), initially at 2 bar pressure, is compressed at a constant temperature of 600 K in two steps : first against a constant external pressure of P bar $(2<\mathrm{P}<8)$, and then against constant external pressure of 8 bar. At each step, the compression is st …

List-I contains various physical/chemical processes, and List-II contains combinations of changes in enthalpy $(\Delta \mathrm{H})$ and entropy $(\Delta \mathrm{S})$. Match each entry in List-I to appropriate entry in List-II, and choose the correct option.

| List-I | | List …

Considering ideal gas behavior, the expansion work done (in kJ) when 144 g of water is electrolyzed completely under constant pressure at 300 K is ____.

Use: Universal gas constant $(\mathrm{R})=8.3\mathrm{J}{\mathrm{K}}^{-1}{\mathrm{mol}}^{-1}$; Atomic mass (in amu): …

Consider the following volume-temperature (V - T) diagram for the expansion of 5 moles of an ideal monoatomic gas.

(see diagram)

Considering only P-V work is involved, the total change in enthalpy (in Joule) for the transformation of state in the sequence …

The entropy versus temperature plot for phases $\alpha$ and $\beta$ at 1 bar pressure is given.
${\mathrm{S}}_{\mathrm{T}}$ and ${\mathrm{S}}_0$ are entropies of the phases at temperatures T and 0 K, respectively.

(see diagram)

The transition temperature for $\alpha$ to …

The entropy versus temperature plot for phases $\alpha$ and $\beta$ at 1 bar pressure is given.
${\mathrm{S}}_{\mathrm{T}}$ and ${\mathrm{S}}_0$ are entropies of the phases at temperatures T and 0 K, respectively.

(see diagram)

The transition temperature for $\alpha$ to …

One mole of an ideal monoatomic gas undergoes two reversible processes (A → B and B → C) as shown in the given figure:

(see figure)

$\mathrm{A}\to \mathrm{B}$ is an adiabatic process. If the total heat absorbed in the entire process ( …

In a one-litre flask, 6 moles of A undergoes the reaction A (g) ⇌P (g). The progress of product formation at two temperatures (in Kelvin), ${\mathrm{T}}_1$ and ${\mathrm{T}}_2$, is shown in the figure:

(see figure)

If ${\mathrm{T}}_1=2{\mathrm{T}}_2$ and …

2 mol of Hg(g) is combusted in a fixed volume bomb calorimeter with excess of ${\mathrm{O}}_2$ at 298 K and 1 atm into HgO(s). During the reaction, temperature increases from 298.0 K to 312.8 K. If heat capacity of the bomb calorimeter and enthalpy of formation of …

The correct option(s) about entropy (S) is(are)
[R = gas constant, F = Faraday constant, T = Temperature]

For the reaction $\mathbf{X}(\mathrm{s})\rightleftharpoons \mathbf{Y}(\mathrm{s})+\mathbf{Z}(\mathrm{g})$, the plot of $\ln \frac{{\mathrm{p}}_{\mathrm{z}}}{{\mathrm{p}}^{\ominus }}$ versus $\frac{10^4}{T}$ is given below (in solid line), where ${\mathrm{p}}_{\mathrm{z}}$ is the pres …

For the reaction $\mathbf{X}(\mathrm{s})\rightleftharpoons \mathbf{Y}(\mathrm{s})+\mathbf{Z}(\mathrm{g})$, the plot of $\ln \frac{{\mathrm{p}}_{\mathrm{z}}}{{\mathrm{p}}^{\ominus }}$ versus $\frac{10^4}{T}$ is given below (in solid line), where ${\mathrm{p}}_{\mathrm{z}}$ is the pres …

An ideal gas undergoes a reversible isothermal expansion from state I to state II followed by a reversible adiabatic expansion from state II to state III. The correct plot(s) representing the changes from state I to state III is(are)
($p$: pressure, $V$: volume, $T$: temperature, …

The amount of energy required to break a bond is same as the amount of energy released when the same bond is formed. In gaseous state, the energy required for homolytic cleavage of a bond is called Bond Dissociation Energy (BDE) or Bond Strength. BDE is affected by $s$-characte …

The amount of energy required to break a bond is same as the amount of energy released when the same bond is formed. In gaseous state, the energy required for homolytic cleavage of a bond is called Bond Dissociation Energy (BDE) or Bond Strength. BDE is affected by $s$-characte …

One mole of an ideal gas at 900 K , undergoes two reversible processes, I followed by II, as shown below. If the work done by the gas in the two processes are same, the value of $\ln \frac{V_3}{V_2}$ is ____.

( $U$ : internal energy, $S$ : entropy, $p$ : pressure, …

Consider the reaction $\mathbf{A}\rightleftharpoons \mathbf{B}$ at 1000 K. At time ${\mathrm{t}}^{\prime }$, the temperature of the system was increased to 2000 K and the system was allowed to reach equilibrium. Throughout this experiment the partial pressure of A was maintained at 1 bar. …

Choose the reaction(s) from the following options, for which the standard enthalpy of reaction is equal to the standard enthalpy of formation.

A reversible cyclic process for an ideal gas is shown below. Here, $P,V$, and $T$ are pressure, volume and temperature, respectively. The thermodynamic parameters $q,w,H$ and $U$ are heat, work, enthalpy and internal energy, respectively.

The correct option(s) is (are …

A closed tank has two compartments A and B, both filled with oxygen (assumed to be ideal gas). The partition separating the two compartments is fixed and is a perfect heat insulator (Figure 1). If the old partition is replaced by a new partition which can slide and conduct heat b …

For a reaction, $\mathrm{A}\rightleftharpoons \mathrm{P}$, the plots of $[\mathrm{A}]$ and $[\mathrm{P}]$ with time at temperatures $T_1$ and $T_2$ are given below.

If $T_2>T_1$, the correct statement(s) is (are)
(Assume $\Delta H^{\theta }$ and $\Delta S^{\theta }$ are i …

Consider the following reversible reaction,

$\mathrm{A}(\mathrm{g})+\mathrm{B}(\mathrm{g})\rightleftharpoons \mathrm{AB}(\mathrm{g})$

The activation energy of the backward reaction exceeds that of the forward reaction by $2RT$ (in $\mathrm{J}{\mathrm{mol}}^{-1}$). If the pre-exp …

The standard state Gibbs free energies of formation of C (graphite) and C (diamond) at $\mathrm{T}=298\mathrm{K}$ are …

For a reaction taking place in a container in equilibrium with its surroundings, the effect of temperature on its equilibrium constant $K$ in terms of change in entropy is described by

An ideal gas is expanded from $(p_1,V_1,T_1)$ to $(p_2,V_2,T_2)$ under different conditions. The correct statement(s) among the following is(are)

One mole of an ideal gas at 300 K in thermal contact with surroundings expands isothermally from 1.0 L to 2.0 L against a constant pressure of 3.0 atm. In this process, the change in entropy of surroundings ($\Delta S_{\text{surr}}$) in ${\mathrm{JK}}^{-1}$ is
(1 L atm = 101.3 J)

Match the thermodynamic processes given under Column I with the expressions given under Column II.
| (B) | Expansion of 1 mol of an ideal gas into a vacuum und …

PARAGRAPH 2

When 100 mL of 1.0 M HCl was mixed with 100 mL of 1.0 M NaOH in an insulated beaker at constant pressure, a temperature increase of 5.7 °C was measured for the beaker and its contents (Expt. 1). Because the enthalpy of neutralization of a strong acid with a strong ba …

An ideal gas in a thermally insulated vessel at internal pressure $=P_1$, volume $=V_1$ and absolute temperature $=T_1$ expands irreversibly against zero external pressure, as shown in the diagram. The final internal pressure, volume and absolute temperature of the gas are …

For the process

at $T=100^{\circ }\mathrm{C}$ and 1 atmosphere pressure, the correct choice is

The standard enthalpies of formation of $C{O}_2(g),H_{2}O(l)$ and glucose $(s)$ at 25 °C are $-400kJ/mol,-300kJ/mol$ and $-1300kJ/mol$, respectively. The standard enthalpy of combustion per gram of glucose at 25 °C is

Benzene and naphthalene form an ideal solution at room temperature. For this process, the true statement(s) is(are)

Using the data provided, calculate the multiple bond energy $\left(\mathrm{kJ}{\mathrm{mol}}^{-1}\right)$ of a $\mathrm{C}\equiv \mathrm{C}$ bond in ${\mathrm{C}}_2{\mathrm{H}}_2$. That energy is (take the bond energy of a C-H bond as …

The reversible expansion of an ideal gas under adiabatic and isothermal conditions is shown in the figure. Which of the following statement(s) is (are) correct?

For an ideal gas, consider only $P-V$ work in going from an initial state $X$ to the final state $Z$. The final state $Z$ can be reached by either of the two paths shown in the figure. Which of the following choice(s) is (are) correct ? [take $\Delta S$ as change in ent …

Match the transformations in column I with appropriate options in column II
| (B) …

The species which by definition has ZERO standard molar enthalpy of formation at 298 K is

The bond energy (in $\mathbf{kcal}{\mathbf{mol}}^{-1}$) of a C-C single bond is approximately

Among the following, the intensive property is (properties are)

One mole of an ideal gas is taken from a to b along two paths denoted by the solid and the dashed lines as shown in the graph below. If the work done along the solid line path is ${\mathrm{w}}_{\mathrm{s}}$ and that along the dotted line path is ${\mathrm{w}}_{\mathrm{d}}$, then …

Among the following, the state function(s) is(are)

In a constant volume calorimeter, 3.5 g of a gas with molecular weight 28 was burnt in excess oxygen at 298.0 K. The temperature of the calorimeter was found to increase from 298.0 K to 298.45 K due to the combustion process. Given that the heat capacity of the calorimeter is …

STATEMENT-1 : For every chemical reaction at equilibrium, standard Gibbs energy of reaction is zero.
and
STATEMENT-2 : At constant temperature and pressure, chemical reactions are spontaneous in the direction of decreasing Gibbs energy.

STATEMENT-1: There is a natural asymmetry between converting work to heat and converting heat to work.
and
STATEMENT-2: No process is possible in which the sole result is the absorption of heat from a reservoir and its complete conversion into work.

For the process ${\mathrm{H}}_2\mathrm{O}(l)(1\mathrm{bar},373\mathrm{K})\to {\mathrm{H}}_2\mathrm{O}(g)(1$ bar, $373\mathrm{K})$, the correct set of thermodynamic parameters is

A monatomic ideal gas undergoes a process in which the ratio of P to V at any instant is constant and equals to 1. What is the molar heat capacity of the gas?

The direct conversion of A to B is difficult, hence it is carried out by the following shown path:

Given $\Delta {\mathrm{S}}_{(\mathrm{A}\to \mathrm{C})}=50$ e.u.
$\Delta {\mathrm{S}}_{(\mathrm{C}\to \mathrm{D})}=30$ e.u. …

For the reaction, $2\mathrm{CO}+{\mathrm{O}}_2⟶2{\mathrm{CO}}_2;\Delta \mathrm{H}=-560\mathrm{kJ}$. Two moles of CO and one mole of ${\mathrm{O}}_2$ are taken in a container of volume 1 L . They completely form two moles of ${\mathrm{CO}}_2$, the gases devia …