JEE Main PYQs — Thermodynamics

Two vessels A and B are connected via stopcock. Vessel A is filled with a gas at a certain pressure. The entire assembly is immersed in water and allowed to come to thermal equilibrium. After opening…

Arrange the following in order of magnitude of work done by the system / on the system at constant temperature: (a) |Wreversible| for expansion in infinite stage. (b) |Wirreversible| for expansion in…

Which of the following graphs correctly represents the variation of thermodynamic properties of Haber's process? (N2(g) + 3H2(g) <=> 2NH3(g))

500 J of energy is transferred as heat to 0.5 mol of Argon gas at 298 K and 1.00 atm. The final temperature and the change in internal energy respectively are: (Given: R = 8.3 J K-1 mol-1)

If C(diamond) -> C(graphite) + X kJ mol-1 C(diamond) + O2(g) -> CO2(g) + Y kJ mol-1 C(graphite) + O2(g) -> CO2(g) + Z kJ mol-1 At constant temperature. Then:

Total enthalpy change for freezing of 1 mol of water at 10°C to ice at -10°C is _____. Given: fusH = x\ kJ/mol Cp[H2O(l)] = y\ J mol-1K-1 Cp[H2O(s)] = z\ J mol-1K-1

The correct statement amongst the following is: (A) The term 'standard state' implies that the temperature is 0°C (B) The standard state of pure gas is the pure gas at a pressure of 1 bar and…

Let us consider a reversible reaction at temperature T. In this reaction, both H and S were observed to have positive values. If the equilibrium temperature is Te, then the reaction becomes…

One mole of an ideal gas expands isothermally and reversibly from 10 dm3 to 20 dm3 at 300 K. U, q and work done in the process respectively are: Given: R = 8.3 JK-1 and mol-1 In 10 = 2.3, 2 = 0.30, 3…

Consider the given data: (A) HCl(g) + 10H2O(l) -> HCl.10H2O, H = -69.01 kJ mol-1 (B) HCl(g) + 40H2O(l) -> HCl.40H2O, H = -72.79 kJ mol-1 Choose the correct statement:

An ideal gas undergoes a cyclic transformation starting from the point A and coming back to the same point by tracing the path A B C D A as shown in three p-V diagram cases. Choose the correct option…

Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at boiling point of water. Choose the correct option. (a) Both H…

Which of the following is not correct?

Choose the correct option for free expansion of an ideal gas under adiabatic condition:

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Enthalpy of neutralisation of strong monobasic acid with strong monoacidic…

What happens when methane undergoes combustion in in systems A and B respectively? System A: Adiabatic container System B: Diathermic container

Which of the following relations are correct? (A) U = q + p V (B) G = H - T S (C) S = qrevT (D) H = U - nRT

Which of the following relation is not correct?

Given: (A) 2CO(g) + O2(g) 2CO2(g), H1 = -x\,kJ mol-1 (B) C(graphite) + O2(g) CO2(g), H2 = -y\,kJ mol-1 The H for the reaction C(graphite) + 12O2(g) CO(g) is:

The enthalpy change for the adsorption process and micelle formation respectively are:

The incorrect statements from the following is:

At STP, Enthalpy of combustion of benzene (l) and acetylene (g) are -3268 and -1300\,kJ mol-1 respectively. The H for 3C2H2(g) C6H6(l) is:

Assertion A: Reduction of metal oxide is easier if metal formed is in liquid state than solid state. Reason R: G becomes more negative as entropy is higher in liquid state than solid state.

At 25C and 1 atm pressure, the enthalpies of combustion are as given below: | Substance | H2 | C (graphite) | C2H6(g) | |-----------|------|------|------| | c H/kJ mol-1 | -286.0 | -394.0 | -1560.0 |…

C(s) + O2(g) CO2(g) + 400\,kJ; C(s) + 12O2(g) CO(g) + 100\,kJ When coal of purity 60% is allowed to burn in presence of insufficient oxygen, 60% of carbon is converted into 'CO' and the remaining is…

During which of the following processes does entropy decrease? (A) Freezing of water to ice at 0C (B) Freezing of water to ice at -10C (C) N2(g)+3H2(g)2NH3(g) (D) Adsorption of CO(g) on lead surface…

The incorrect expression among the following is: (1) For isothermal process wreversible = -nRTVfVi (2) K = H - T SRT (3) GSystem STotal = -T (at constant P) (4) K = e- G/RT

At 298.2 K the relationship between enthalpy of bond dissociation (in kJ mol-1) for hydrogen (EH) and its isotope, deuterium (ED), is best described by:

For one mole of an ideal gas, which of these statements must be true? (a) Internal energy (U) and enthalpy (H) each depends on temperature. (b) Compressibility factor Z is not equal to 1. (c) CP,m -…

Lattice enthalpy and enthalpy of solution of NaCl are 788 and 4\,kJ mol-1 respectively. The hydration enthalpy of NaCl is:

For a reaction 4M(s) + nO2(g) 2M2On(s), the free energy change is plotted as a function of temperature. The temperature below which the oxide is stable could be inferred from the plot as the point at…

Five moles of ideal gas at 1 bar and 298 K is expanded into vacuum to double the volume. The work done is:

The true statement amongst the following is:

If enthalpy of atomization for Br2(l) is x\,kJ/mol and bond enthalpy for Br2 is y\,kJ/mol, the relation between them:

The variation of equilibrium constant with temperature is given below: | Temperature | Equilibrium Constant | |-------------|---------------------| | T1 = 25C | K1 = 10 | | T2 = 100C | K2 = 100 | The…

An ideal gas is allowed to expand from 1 L to 10 L against a constant external pressure of 1 bar. The work done in kJ is:

Among the following, the set of parameters that represents path functions is: (i) q + w &nbsp;&nbsp (ii) q &nbsp;&nbsp (iii) w &nbsp;&nbsp (iv) H - TS

Which one of the following equations does not correctly represent the first law of thermodynamics for the given processes involving an ideal gas? (Assume non-expansion work is zero)

A process will be spontaneous at all temperatures if:

The incorrect match in the following is:

Given: (i) C(graphite) + O2(g) CO2(g); H = x (ii) C(graphite) + 12O2(g) CO(g); H = y (iii) CO(g) + 12O2(g) CO2(g); H = z Which algebraic relationship is correct?

For a diatomic ideal gas in a closed system, which plot does NOT correctly describe the relation between various thermodynamic quantities?

Combination of plots which does NOT represent isothermal expansion of an ideal gas is:

Consider the reversible isothermal expansion of an ideal gas in a closed system at two different temperatures T1 and T2 (T1<T2). Correct graph of work done w vs final volume V:

5 moles of an ideal gas at 100 K are allowed to undergo reversible compression till its temperature becomes 200 K. If CV = 28\,J K-1mol-1 and R = 8.0\,J K-1mol-1), the values of U and (pV) for this…

An ideal gas undergoes isothermal compression from 5\,m3 to 1\,m3 against a constant external pressure of 4\,N m-2. Heat released = 24\,J mol-1K-1 & is used to increase the pressure of 1 mol Al.…

During compression of a spring the work done is 10 kJ and 2 kJ escaped to the surroundings as heat. The change in internal energy, U (kJ) is:

The standard reaction Gibbs energy for a chemical reaction at an absolute temperature T is given by G = A - BT, where A and B are non-zero constants. Which of the following is true about this…

For the chemical reaction X Y, the standard reaction Gibbs energy depends on temperature T (in K) as r G\,(in kJ mol-1) = 120 - 38T. The major component of the reaction mixture at T is:

The reaction MgO(s) + C(s) Mg(s) + CO(g), for which H = +491.1\,kJ mol-1 and S = 198.0\,JK-1mol-1, is not feasible at 298 K. Temperature above which reaction will be feasible is:

The process with negative entropy change is:

Two blocks of same metal having same mass and at T1 and T2 , respectively, are brought in contact with each other and allowed to reach thermal equilibrium at constant pressure. The change of entropy,…

A process has H = 200\,J mol-1 and S = 40\,JK-1mol-1. Out of the values given below, choose the minimum temperature above which the process will be spontaneous:

For the equilibrium 2H2O H3O+ + OH-; the value of G at 298 K is approximately:

The entropy change associated with the conversion of 1 kg of ice at 273 K to water vapours at 383 K is ______. (Specific heat of water liquid and water vapour are 4.2\,kJ K-1 and 2.0\,kJ K-1kg-1;…

Enthalpy of sublimation of iodine is 24\,cal g-1 at 200C. If specific heat of I2(s) and I2 (vap) are 0.055 and 0.031\,cal g-1K-1 respectively, then enthalpy of sublimation of iodine at 250C in cal…

The difference between H and U is ( H - U), when the combustion of one mole of heptane (l) is carried out at a temperature T, is equal to:

For silver, Cp\,(JK-1mol-1) = 23 + 0.01T. If the temperature (T) of 3 moles of silver is raised from 300 K to 1000 K at 1 atm pressure, the value of H will be close to: