Thermodynamics

1.0 mol of monoatomic ideal gas is expanded from state 1 to state 2 as shown in the figure. The magnitude of the work done for the expansion of gas from state 1 to state 2 at 300 K is ____________ J. (Nearest integer)
(Given : R = 8.3 J K$...

\(\Delta\)G\(^\circ\) vs T plot for the formation of MgO, involving reaction 2Mg + O2 \(\to\) 2MgO, will look like :

17.0 g of NH3 completely vapourises at \(-\)33.42\(^\circ\)C and 1 bar pressure and the enthalpy change in the process is 23.4 kJ mol\(-\)1. The enthalpy change for the vapourisation of 85 g of NH3 under the same conditions is _________ kJ.

2.2 g of nitrous oxide (N2O) gas is cooled at a constant pressure of 1 atm from 310 K to 270 K causing the compression of the gas from 217.1 mL to 167.75 mL. The change in internal energy of the process, \(\Delta\)U is '\(-\)x' J. The value...

When 600 mL of 0.2 M HNO3 is mixed with \(400 \mathrm{~mL}\) of 0.1 M NaOH solution in a flask, the rise in temperature of the flask is ___________ \(\times 10^{-2}{ }\,^{\circ} \mathrm{C}\).
(Enthalpy of neutralisation $$=57 \mathrm{~kJ} \...

4.0 L of an ideal gas is allowed to expand isothermally into vacuum until the total volume is 2.0 L. The amount of heat absorbed in this expansion is ____________ L atm.

For combustion of one mole of magnesium in an open container at 300 K and 1 bar pressure, \(\Delta\)CH\(\Theta\) = \(-\)601.70 kJ mol\(-\)1, the magnitude of change in internal energy for the reaction is __________ kJ. (Nearest integer)
(G...

Which of the following relation is not correct?

Among the following the number of state variables is ______________.
Internal energy (U)
Volume (V)
Heat (q)
Enthalpy (H)

Given below are two statements: One is labelled as Assertion \(\mathbf{A}\) and the other is labelled as Reason \(\mathbf{R}\)
Assertion A : The reduction of a metal oxide is easier if the metal formed is in liquid state than solid state.
R...

Match List-I with List-II.

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When 5 moles of He gas expand isothermally and reversibly at 300 K from 10 litre to 20 litre, the magnitude of the maximum work obtained is __________ J. [nearest integer] (Given : R = 8.3 J K\(-\)1 mol\(-\)1 and log 2 = 0.3010)

The molar heat capacity for an ideal gas at constant pressure is \(20.785 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\). The change in internal energy is \(5000 \mathrm{~J}\) upon heating it from \(300 \mathrm{~K}\) to $$500 \mathrm{~K}...

A gas (Molar mass = 280 \(\mathrm{~g} \mathrm{~mol}^{-1}\)) was burnt in excess \(\mathrm{O}_{2}\) in a constant volume calorimeter and during combustion the temperature of calorimeter increased from \(298.0 \mathrm{~K}\) to \(298.45\) $$\m...

For complete combustion of methanol
CH3OH(I) + \({3 \over 2}\)O2(g) \(\to\) CO2(g) + 2H2O(I)
the amount of heat produced as measured by bomb calorimeter is 726 kJ mol\(-\)1 at 27\(^\circ\)C. The enthalpy of combustion for the reaction is $$...

A fish swimming in water body when taken out from the water body is covered with a film of water of weight 36 g. When it is subjected to cooking at 100\(^\circ\)C, then the internal energy for vaporization in kJ mol\(-\)1 is ___________. [n...

\(2.4 \mathrm{~g}\) coal is burnt in a bomb calorimeter in excess of oxygen at \(298 \mathrm{~K}\) and \(1 \mathrm{~atm}\) pressure. The temperature of the calorimeter rises from \(298 \mathrm{~K}\) to \(300 \mathrm{~K}\). The enthalpy chan...

For the reaction
\(\mathrm{H}_{2} \mathrm{F}_{2}(\mathrm{~g}) \rightarrow \mathrm{H}_{2}(\mathrm{~g})+\mathrm{F}_{2}(\mathrm{~g})\)
\(\Delta U=-59.6 \mathrm{~kJ} \mathrm{~mol}^{-1}\) at \(27^{\circ} \mathrm{C}\).
The enthalpy change for the...

The standard entropy change for the reaction
4Fe(s) + 3O2(g) \(\to\) 2Fe2O3(s) is \(-\)550 J K\(-\)1 at 298 K.
[Given : The standard enthalpy change for the reaction is \(-\)165 kJ mol\(-\)1]. The temperature in K at which the reaction att...

At 25\(^\circ\)C and 1 atm pressure, the enthalpy of combustion of benzene (I) and acetylene (g) are \(-\) 3268 kJ mol\(-\)1 and \(-\)1300 kJ mol\(-\)1, respectively. The change in enthalpy for the reaction 3 C2H2(g) \(\to\) C6H6 (I), is :

The enthalpy of combustion of propane, graphite and dihydrogen at \(298 \mathrm{~K}\) are \(-2220.0 \mathrm{~kJ} \mathrm{~mol}^{-1},-393.5 \mathrm{~kJ} \mathrm{~mol}^{-1}\) and \(-285.8 \mathrm{~kJ} \mathrm{~mol}^{-1}\) respectively. The ma...

While performing a thermodynamics experiment, a student made the following observations.
HCl + NaOH \(\to\) NaCl + H2O \(\Delta\)H = \(-\)57.3 kJ mol\(-\)1
CH3COOH + NaOH \(\to\) CH3COONa + H2O \(\Delta\)H = \(-\)55.3 kJ mol\(-\)1
The entha...

At 25\(^\circ\)C and 1 atm pressure, the enthalpies of combustion are as given below :

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The incorrect expression among the following is :

For water at 100\(^\circ\) C and 1 bar,\(\Delta\)vap H \(-\) \(\Delta\)vap U = _____________ \(\times\) 102 J mol\(-\)1. (Round off to the Nearest Integer)[Use : R = 8.31 J mol\(-\)1 K\(-\)1][Assume volume of H2O(l) is much smaller than vol...

When 400 mL of 0.2 M H2SO4 solution is mixed with 600 mL of 0.1 M NaOH solution, the increase in temperature of the final solution is __________ \(\times\) 10\(-\)2 K. (Round off to the nearest integer).[Use : H+ (aq) + OH\(-\) (aq) \(\to\)...

200 mL of 0.2 M HCl is mixed with 300 mL of 0.1 M NaOH. The molar heat of neutralization of this reaction is \(-\)57.1 kJ. The increase in temperature in \(^\circ\)C of the system on mixing is x \(\times\) 10\(-\)2. The value of x is ______...

Data given for the following reaction is as follows :FeO(s) + C(graphite) \(\to\) Fe(s) + CO(g)
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Two flasks I and II shown below are connected by a valve of negligible volume.When the valve is opened, the final pressure of the system in bar is x \(\times\) 10\(-\)2. The value of x is __________. (Integer answer)[Assume - Ideal gas; 1 b...

For a chemical reaction A + B ⇌ C + D(\({\Delta _r}{H^\Theta }\) = 80 kJ mol\(-\)1) the entropy change \({\Delta _r}{S^\Theta }\) depends on the temperature T (in K) as \({\Delta _r}{S^\Theta }\) = 2T (J K\(-\)1mol\(-\)1).Minimum temperatur...

An exothermic reaction X \(\to\) Y has an activation energy 30 kJ mol\(-\)1. If energy change \(\Delta\)E during the reaction is \(-\)20 kJ, then the activation energy for the reverse reaction in kJ is ___________. (Integer answer)

The average S-F bond energy in kJ mol\(-\)1 of SF6 is _____________. (Rounded off to the nearest integer)[Given : The values of standard enthalpy of formation of SF6(g), S(g) and F(g) are - 1100, 275 and 80 kJ mol\(-\)1 respectively.]

The Born-Haber cycle for KCl is evaluated with the following data :\({\Delta _f}{H^\Theta }\) for KCl = \(-\)436.7 kJ mol\(-\)1 ;\({\Delta _{sub}}{H^\Theta }\) for K = 89.2 kJ mol\(-\)1 ;\({\Delta _{ionization}}{H^\Theta }\) for K = 419.0 k...

For water \(\Delta\)vap H = 41 kJ mol\(-\)1 at 373 K and 1 bar pressure. Assuming that water vapour is an ideal gas that occupies a much larger volume than liquid water, the internal energy change during evaporation of water is ___________ ...

At 298 K, the enthalpy of fusion of a solid (X) is 2.8 kJ mol\(-\)1 and the enthalpy of vaporisation of the liquid (X) is 98.2 kJ mol\(-\)1. The enthalpy of sublimation of the substance (X) in kJ mol\(-\)1 is _____________. (in nearest inte...

A system does 200 J of work and at the same time absorbs 150 J of heat. The magnitude of the change in internal energy is ____________ J. (Nearest integer)

The ionization enthalpy of Na+ formation from Na(g) is 495.8 kJ mol\(-\)1, while the electron gain enthalpy of Br is \(-\)325.0 kJ mol\(-\)1. Given the lattice enthalpy of NaBr is \(-\)728.4 kJ mol\(-\)1. The energy for the formation of NaB...

The reaction of cyanamide, NH2CN(s) with oxygen was run in a bomb calorimeter and \(\Delta\)U was found to be \(-\)742.24 kJ mol\(-\)1. The magnitude of \(\Delta\)H298 for the reaction$$N{H_2}C{H_{(S)}} + {3 \over 2}{O_{2(g)}} \to {N_{2(g)}...

Five moles of an ideal gas at 293 K is expanded isothermally from an initial pressure of 2.1 MPa to 1.3 MPa against at constant external pressure 4.3 MPa. The heat transferred in this process is _________ kJ mol\(-\)1. (Rounded off to the n...

Assuming ideal behaviour, the magnitude of log K for the following reaction at 25\(^\circ\)C is x \(\times\) 10\(-\)1. The value of x is ______________. (Integer answer)
\(3HC \equiv C{H_{(g)}} \rightleftharpoons {C_6}{H_{6(l)}}\)
[Given : ...

If the standard molar enthalpy change for combustion of graphite powder is \(-\)2.48 \(\times\) 102 kJ mol\(-\)1, the amount of heat generated on combustion of 1 g of graphite powder is ___________ kJ. (Nearest integer)

For a given chemical reaction A \(\to\) B at 300 K the free energy change is \(-\)49.4 kJ mol\(-\)1 and the enthalpy of reaction is 51.4 kJ mol\(-\)1. The entropy change of the reaction is _____________ JK\(-\)1 mol\(-\)1.

For the reaction, 2NO2(g) \(\rightleftharpoons\) N2O4(g), when \(\Delta\)S = \(-\)176.0 JK\(-\)1 and \(\Delta\)H = \(-\)57.8 kJ mol\(-\)1, the magnitude of \(\Delta\)G at 298 K for the reaction is ___________ kJ mol\(-\)1. (Nearest integer)

For the reaction C2H6 \(\to\) C2H4 + H2the reaction enthalpy \(\Delta\)rH = __________ kJ mol\(-\)1. (Round off to the Nearest Integer).[ Given : Bond enthalpies in kJ mol\(-\)1 : C-C : 347, C = C : 611; C-H : 414, H-H : 436 ]

The standard enthalpies of formation of Al2O3 and CaO are \(-\)1675 kJ mol-1 and \(-\)635 kJ mol\(-\)1 respectively.For the reaction3CaO + 2Al \(\to\) 3Ca + Al2O3 the standard reaction enthalpy \(\Delta\)rH0 = _________ kJ.(Round off to t...

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

At 25\(^\circ\)C, 50 g of iron reacts with HCl to form FeCl2. The evolved hydrogen gas expands against a constant pressure of 1 bar. The work done by the gas during this expansion is _________ J. (Round off to the Nearest Integer).[Given : ...

If enthalpy of atomisation for Br2(1) is x kJ/mol
and bond enthalpy for Br2 is y kJ/mol, the
relation between them :

The true statement amongst the following is :

The magnitude of work done by a gas that undergoes a reversible expansion along the path ABC shown in
the figure is _______.