Thermodynamics

One gram sample NH₄NO₃ is decomposed in a bomb calorimeter.The temperature of the calorimeter increases by 6.12K.The heat capacity of the system is 1.23kJ/g/deg.What is the molar heat of decomposition for NH₄NO₃

Which one of the following has ΔS⁰ greater then zero

How much energy is released when 6 moles of octane is burnt in air? Given ΔH°f for CO₂(g), H₂O(g) and C₈H₁₈respectively are -490, -240 and +160 kJ/mol

ΔH°f (298 K) of methanol is given by the chemical equation

For the reaction one of the mole of zinc dust with one mole of sulphuric acid in a bomb calorimeter, ΔU and w coorespond to

For a spontaneous process the correct statement is

In an isobaric process,when temperature changes from T₁ to T₂, ΔS is equal to

For adiabatic process,which is correct

Which of the following is not a thermodynamic function

At standard state Gibb’s free energy change for isomerization reaction cis-2-pentene⇌trance-2-pentene is -3.67 kJ/mol at 400K. If more trans-2-pentene is added to the reaction vessel then

For a reaction to occur spontaneously

Which of the following is the correct equation

One mole of an ideal gas at 300 K is expanded isothermally from an initial volum of 1 litre to 10 litres .The ΔE for this process is

For the cell reaction
Cu²⁺ (C₁.aq) + Zn(s) = Zn²⁺(C₂.aq ) + Cu(s)
of an electrochemical cell, the change in free Energy (ΔG) at a given temperature is a function of

For the reaction
C₂H₅OH + 3O₂(g) → 2CO₂(g) + 3H₂O which one is true

Cell reaction is spontaneous when

At 27⁰C latent heat of fusion of a compound is 2930 J/mol. Entropy change is

Change in enthalpy for reaction,
2H₂O₂ → 2H₂O + O₂
if heat of formation of H₂O₂ and H₂O are -188 and -286 kJ/mol respectively,is

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

Enthalpy of CH₄ + ¹/² O₂ → CH₃OH is negative. If enthalpy of combustion of CH₄ and CH₃OH are x and y respectively. Then which relation is correct

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 ΔH for C(s) , H₂(g)and CH₄(g) are -94, -68 and -213 kcal/mol. Then ΔH for C(s) + 2H₂(g) → CH₄(g)is

Unit of entropy is

What is the entropy change (in J K⁻¹ mol⁻¹) when one mole of ice is converted into water at 0⁰C? (The enthalpy change for the conversion of ice to liquid water is 6.0 kJ mol⁻¹ at 0⁰C).

For which one of the following equations is ΔH⁰react equal to ΔH°f for the product

The mole heat capacity of water at constant pressure, C, is 75 J K⁻¹mol⁻¹. When 1.0 kJ of heat is supplied to 100g of water which is free to expand, the increases in temperature of water is

IF the bond energies of H – H , Br – Br and H – Br are 433 , 192 and 364 kJ mol⁻¹ respectively, the ΔH° for the reaction
H₂(g) + Br₂(g) → 2HBr(g) 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 (1atm = 101.32 J)

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, respectively. Standard Gibbs energy change for the same reaction at 298 k is

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

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

A reaction occurs spontaneously is

The absolute enthalpy of neutralisation of the reaction
MgO(s) + 2HCl(aq) → MgCl₂(aq) + H₂O(l) will be

For an endothermic reaction, energy of activation is Ea and enthalpy of reaction is ΔH (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 ⇌ XY₃,ΔH = -30 kJ, to be at equilibrium ,the temperature should be

For vaporization of water at 1 atmospheric pressure, the values of ΔH and ΔS are 40.63 kJ mol⁻¹ and 108.8 JK⁻¹ mol⁻¹ ,respectively. The temperature when Gibb’s energy change ( ΔG) for this transformation will be zero, is

If the enthalpy change for the transition of liquid water to steam is 30 kJ mol⁻¹ at 27⁰C, the entropy change for the process would be

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

In which of the following reaction standard entropy change (ΔS⁰) is positive and standard Gibb’s energy change (ΔG⁰) 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 0⁰C is

Standard enthalpy of vaporisation Δvap H⁰ for water at 100⁰C is 40.66 kJ mol⁻¹. The internal energy of vaporisation of water at 100⁰C (in kJ mol⁻¹) is

For isothermal change in the case of an ideal gas

For spontaneous reaction

The work done in expansion of an ideal gas from an initial volume v1 to a final v2 litres against a pressure of 1atm at 300 K is

Which of the following depends on the path followed

Consider the modes of transformations of a gas from state ‘A’ to state ‘B’ as
Which one of the following is true

The equation ΔG = ΔH – TΔS is for

A corked flask containing boiling water and its vapour is allowed to cool down to room temperature. If water and its vapour as a whole is the system then

At 0K, (i) ¹²C and (ii) a mixture of ¹²C and ¹⁴C will

For the reaction 2SO₃(g) → 2SO₂(g) + O₂(g) the entropy change (ΔG) is

In which of the following conditions a chemical reaction can not occur

If the melting point of ice is 0⁰C and latent heat of fusion is 5.46 kJ mol⁻¹, the entropy change for the conversion of 18 g of ice to water at one atmosphere is

The internal energy of a system is the sum of

One mole of a gas absorbs 300 J of heat at constant volume and its temperature is raised from 30 to 35⁰C. The value of ΔE is

Two moles of an ideal gas expand spontaneously into a vacuum. The work done is

Which of the following equations describe the first law of thermodynamics

The entropy change in the conversion of a solid into its different states can be obtained by using

In an exothermic reaction

Heat produced on burning 6.3 g of a fule raises the temperature of 1.5 kg of water from 30⁰C to 60⁰C.Given that the specific heat of water is 4.2 J/g ⁰C.Calculate the calorific value of the fuel.

Which experssion is correct for the work done in adiabatic reversible expansion of an ideal gas

The heat of neutralization is the highest in the following case

An open system

At 298 K the enthalpy of formation of liquid water is -285.9 kJ/mol and that of steam -242.8 kJ/mol. The enthalpy of vapourisation of water is

For a spontaneous process, entropy always

For spontaneous cooling of a hot metal rod (system) in air

For a thermodynamically reversible reaction in a galvanic cell at temperature T, which one of the following is false

The difference between ΔH and ΔE at 300 K for the reaction
C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(l)

Which of the following statement is false for an isothermal expansion of an ideal gas

If the value of Cp for nitrogen gas is 7 JK⁻¹mol⁻¹ , then the value of ΔH on heating 28g of nitrogen gas from 0⁰C to 100⁰C at constant pressure will be

For an endothermic reaction the value of ΔS is positive.The reaction is

Heat of formation of H₂O(g) at 25⁰C is -243 kJ,ΔE for the reaction H₂(g) + 1/2 O₂(g) → H₂O(g) at 25⁰C is

For the reaction C(s) + O₂(g)

The standard heat of formation of carbon disulphide (l) given that the standard heat of combustion of carbon(s) , sulphur(s) and carbon disulphide(l) are -393.3, -293.72 and -1108.76 kJ mol⁻¹ respectively is

The values of heat of formation of SO₂ and SO₃ are -298.2 kJ and -98.2 kJ. The heat of formation of this reaction will be SO₂ + (1/2)O₂ → SO₃

If 900 J/g of heat is exchanged at boiling point of water, then what is increase in entropy

The neutralisation of a strong acid by a strong base liberates an amount of energy per mole of H⁺ that

Equal volumes of methanoic acid and sodium hydroxide are mixed, if x is the heat of formation of water, then heat evolved on neutralisation is

An ideal gas at constant temperature and pressure expands and its

Heat of neutralisation of strong acid against strong base is constant and equal to

The change in entropy, ΔS is positive for an endothermic reaction.If enthalpy change ΔH occurs at the same temperature T, then the reaction is feasible

The relationship which describes the variation of vapour pressure with temperature is called