Thermodynamics · Chemistry · NEET

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...

For an endothermic reaction: (A) $$\mathrm{q}_{\mathrm{p}}$$ is negative. (B) $$\Delta_{\mathrm{r}} \mathrm{H}$$ is positive. (C) $$\Delta_r \mathrm{H...

For the following reaction at $$300 \mathrm{~K}$$ $$\mathrm{A}_2(\mathrm{~g})+3 \mathrm{~B}_2(\mathrm{~g}) \rightarrow 2 \mathrm{AB}_3(\mathrm{~g})$$ ...

In which of the following processes entropy increases? A. A liquid evaporates to vapour. B. Temperature of a crystalline solid lowered from $$130 \mat...

Match List I with List II. .tg {border-collapse:collapse;border-spacing:0;} .tg td{border-color:black;border-style:solid;border-width:1px;font-famil...

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 atm...

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_{\...

The equilibrium concentrations of the species in the reaction $$\mathrm{A}+\mathrm{B} \rightleftharpoons \mathrm{C}+\mathrm{D}$$ are $$2,3,10$$ and $$...

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

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$$-$...

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, wh...

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

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

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

Hydrolysis of sucrose is given by the following reaction.Sucrose + H2O ⇌ Glucose + FructoseIf the equilibrium constant (Kc) is 2 $$ \times $$ 1013 at ...

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

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

In which case change in entropy is negative?

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 [Gi...

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 dis...

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 $$\Del...

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 v...

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

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 ...

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 ...

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

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) de...

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...

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

Consider the following processes : .tg {border-collapse:collapse;border-spacing:0;border:none;} .tg td{font-family:Arial, sans-serif;font-size:14px;...

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 ?

Match List I (Equations) with List II (Type of processes) and select the correct option. .tg {border-collapse:collapse;border-spacing:0;border:none...

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

The following two reactions are known Fe2O3(s) + 3CO(g) $$ \to $$ 2Fe(s) + 3CO2(g); $$\Delta $$H = $$-$$ 26.8 kJ FeO(s) + CO(g) $$ \to $$ &nb...

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 b...

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, ...

The values of $$\Delta $$H and $$\Delta $$S for the reaction, C(graphite) + CO2(g) $$ \to $$  2CO(g) are 170 kJ and 170 J K$$-$$1, respect...

From the following bond energies : H $$-$$ H bond energy   : 431.37 kJ mol$$-$$1 C $$=$$ C bond energy   : 60...

Which of the following are not state functions ? (I) q + w     (II) q (III) w     &n...

For the gas phase reaction, PCl5(g)  $$\rightleftharpoons$$ PCl3(g) + Cl2(g) which of the following conditions are correct ? ...

Bond dissociation enthalpy of H2, Cl2 and HCl are 434, 242 and 431 kJ mol$$-$$1 respectively. Enthalpy of formation of HCl is ...

Consider the following reactions : (i) H+(aq) + OH$$-$$(aq) = H2O(l),  $$\Delta $$H = $$-$$ X1 kJ mol$$-$$1 (ii) H2(g) + 1/2O2(g)...

Given that bond energies of H $$-$$ H and Cl $$-$$ Cl are 430 kJ mol$$-$$1 and 240 kJ mol$$-$$1 respectively and $$\Delta $$Hf for HCl is $$-$$ 90 kJ ...

Identify the correct statement for change of Gibb's energy for a system ($$\Delta $$Gsystem) at constant temperature and pressure.

The enthalpy and entropy change for the reaction: Br2(l) + Cl2(g) $$ \to $$ 2BrCl(g) are 30 kJ mol$$-$$1 and 105 J K$$-$$1 mol$$-$$1 respectively. ...

The enthalpy of hydrogenation of cyclohexene is is $$-$$ 119.5 kJ mol$$-$$1. If resonance energy of benzene is $$-$$ 150.4 kJ mol$$-$$1, its enthalpy ...

Assume each reaction is carried out in an open container. For which reaction will $$\Delta $$H = $$\Delta $$E ?

Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction ?

A reaction occurs spontaneously if

The absolute enthalpy of neutralisation of the reaction : Mg(O)(s) + 2HCl(aq) $$ \to $$ MgCl2(aq) + H2O(l) will be ...

If the bond energies of H $$-$$ H, Br $$-$$ Br, and H $$-$$ Br are 433, 192 and 364 kJ mol$$-$$1 respectively, the $$\Delta $$Ho for the reaction H2(g...

Standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are $$-$$ 382.64 kJ mol$$-$$1 and $$-$$ 145.6 kJ mol$$-$$1, respe...

Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is

The work done during the expansion of a gas from a volume of 4 dm3 to 6 dm3 against a constant external pressure of 3 atm is (1 L atm = 101.32 J)...

For the reaction, C3H8(g) + 5O2(g) $$ \to $$ 3CO2(g) + 4H2O(l) at constant temperature, $$\Delta $$H $$-$$ $$\Delta $$E is ...

The densities of graphite and diamond at 298 K are 2.25 and 3.31 g cm$$-$$3, respectively. If the standard free energy difference $$\left( {\Delta {G^...

For which one of the following equations is $$\Delta $$Horeact equal to $$\Delta $$Hof for the product ?

Formation of solution from two components can be considered as (i) Pure solvent $$ \to $$ separated solvent molecules, $$\Delta $$H1 (ii)&n...

The molar heat capacity of water at constant pressure, C, is 75 J K$$-$$1 mol$$-$$1. When 1.0 kJ of heat is supplied to 100 g of water which is free t...

What is the entropy change (in J K$$-$$1 mol$$-$$1) when one mole of ice is converted into water at 0oC? (The enthalpy change for the conversion of ic...

Unit of entropy is

Which reaction is not feasible?

In a closed insulated container a liquid is stirred with a paddle to increase the temperature which of the following is true ?

Heat of combustion $$\Delta $$Ho for C(s), H2(g) and CH4(g) are $$-$$ 94, $$-$$ 68 and $$-$$213 kcal/mol, then $$\Delta $$Ho for C(s) + 2H2(g) $$ \to ...

2 mole of ideal gas at 27oC temperature is expanded reversibly from 2 lit. to 20 lit. Find entropy change. (R = 2 cal/mol K)

Change in enthalpy for reaction, 2H2O2(l) $$ \to $$ 2H2O(l) + O2(g) if heat of formation of H2O2(l) and H2O(l) are $$-$$188 and - 286 kJ/mol res...

When 1 mol of gas is heated at constant volume temperature is raised from 298 to 308 K. Heat supplied to the gas is 500 J. Then which statement is cor...

PbO2  $$ \to $$ PbO; $$\Delta $$G298 < 0 SnO2 $$ \to $$ SnO;  $$\Delta $$G298 > 0 Most probable oxidation state of Pb and Sn will...

Enthalpy of CH4 + $${1 \over 2}$$ O2 $$ \to $$ CH3OH is negative. If enthalpy of combustion of CH4 and CH3OH are x and y respectively. Then which rela...

2Zn + O2 $$ \to $$ 2ZnO;  $$\Delta $$Go = $$-$$ 616 J 2Zn + S2 $$ \to $$ 2ZnS;  $$\Delta $$Go = $$-$$ 293 J S2 + 2O2 $$ \to $$ 2SO...

The entropy change in the fusion of one mole of a solid melting at 27oC (latent heat of fusion is 2930 J mol–1) is :

For the reaction, C2H5OH(l) + 3O2(g) $$ \to $$ 2CO2(g) + 3H2O(l) which one is true...

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