Home
Current Affairs January 2024

What is the correct answer?

4

During a reversible isothermal expansion of an ideal gas, the entropy change is

A. +ve

B. 0

C. -ve

D.

Correct Answer :

A. +ve


Related Questions

What is the correct answer?

4

Pick out the wrong statement.

A. The chemical potential of a pure substance depends upon the temperature and pressure

B. The chemical potential of a component in a system is directly proportional to the escaping tendency of that component

C. The chemical potential of ith species (μi) in an ideal gas mixture approaches zero as the pressure or mole fraction (xi) tends to be zero at constant temperature

D. The chemical potential of species 'i' in the mixture (μi) is mathematically represented as,μi = ∂(nG)/∂ni]T,P,nj where, n, ni and nj respectively denote the total number of moles, moles of ith species and all mole numbers except ith species. 'G' is Gibbs molar free energy

What is the correct answer?

4

Pick out the extensive property out of the following.

A. Surface tension

B. Free energy

C. Specific heat

D. Refractive index

What is the correct answer?

4

Which law of the thermodynamics provides basis for measuring the thermodynamic property?

A. First law

B. Zeroth law

C. Third law

D. Second law

What is the correct answer?

4

Tea kept in a thermos flask is vigorously shaken. If the tea is considered as a system, then its temperature will

A. Increase

B. Decrease

C. Remain unchanged

D. First fall and then rise

What is the correct answer?

4

Entropy of a substance remains constant during a/an __________ change.

A. Reversible isothermal

B. Irreversible isothermal

C. Reversible adiabatic

D. None of these

What is the correct answer?

4

In the ammonia synthesis reaction, N2 + 3H2 2NH3 + 22.4 kcal, the formation of NH3 will be favoured by

A. High temperature

B. Low pressure

C. Low temperature only

D. Both low temperature and high pressure

What is the correct answer?

4

The ammonia synthesis reaction represented by N2 + 3H2 2NH3; ΔH = - 22.4 kcal, is

A. Endothermic

B. Exothermic

C. Isothermal

D. Adiabatic

What is the correct answer?

4

One mole of nitrogen at 8 bar and 600 K is contained in a piston-cylinder arrangement. It is brought to 1 bar isothermally against a resisting pressure of 1 bar. The work done (in Joules) by the gas is

A. 30554

B. 10373

C. 4988.4

D. 4364.9

What is the correct answer?

4

As the time is passing, entropy of the universe

A. Is increasing

B. Is decreasing

C. Remain constant

D. Data insufficient, can't be predicted

What is the correct answer?

4

Trouton's ratio of __________ liquids is calculated using Kistyakowsky equation.

A. Polar

B. Non-polar

C. Both (A) & (B)

D. Neither (A) nor (B)

What is the correct answer?

4

Third law of thermodynamics is helpful in

A. Prediction of the extent of a chemical reaction

B. Calculating absolute entropies of substances at different temperature

C. Evaluating entropy changes of chemical reaction

D. Both (B) and (C)

What is the correct answer?

4

A refrigerator may be termed as a

A. Heat pump

B. Heat engine

C. Carnot engine

D. None of these

What is the correct answer?

4

Pick out the wrong statement.

A. Minimum number of degree of freedom of a system is zero

B. Degree of freedom of a system containing a gaseous mixture of helium, carbon dioxide and hydrogen is 4

C. For a two phase system in equilibrium made up of four non-reacting chemical species, the number of degrees of freedom is 4

D. Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation

What is the correct answer?

4

For the gaseous phase chemical reaction, C2H4(g) + H2O(g) ↔ C2H5OH(g), the equilibrium conversion does not depend on the

A. Steam to ethylene ratio

B. Temperature

C. Pressure

D. None of these

What is the correct answer?

4

Pick out the correct statement.

A. If an insoluble gas is passed through a volatile liquid placed in a perfectly insulated container, the temperature of the liquid will increase

B. A process is irreversible as long as Δ S for the system is greater than zero

C. The mechanical work done by a system is always equal to∫P.dV

D. The heat of formation of a compound is defined as the heat of reaction leading to the formation of the compound from its reactants

What is the correct answer?

4

In a reversible chemical reaction (where, Δx = number of moles of products-number of moles of reactants)

A. Addition of inert gas favours the forward reaction, when Δx is positive

B. Pressure has no effect on equilibrium, when Δn = 0

C. Addition of inert gas has no effect on the equilibrium constant at constant volume for any value of Δx (+ ve, - ve) or zero)

D. All 'a', 'b' & 'c'

What is the correct answer?

4

The compressibility factor of a gas is given by (where, V1 = actual volume of the gas V2 = gas volume predicted by ideal gas law)

A. V1/V2

B. V2/V1

C. V1 - V2

D. V1.V2

What is the correct answer?

4

Enthalpy 'H' is defined as

A. H = E - PV

B. H = F - TS

C. H - E = PV

D. None of these

What is the correct answer?

4

Isentropic process means a constant __________ process.

A. Enthalpy

B. Pressure

C. Entropy

D. None of these

What is the correct answer?

4

The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is

A. Less pronounced

B. More pronounced

C. Equal

D. Data insufficient, can't be predicted

What is the correct answer?

4

Gibbs free energy of a pure fluid approaches __________ as the pressure tends to zero at constant temperature.

A. Infinity

B. Minus infinity

C. Zero

D. None of these

What is the correct answer?

4

Internal energy of an element at 1 atm and 25° C is __________ kcal/kg.mole.

A. 0

B. 273

C. 25

D. None of these

What is the correct answer?

4

During adiabatic expansion of gas

A. Pressure remains constant

B. Pressure is increased

C. Temperature remains constant

D. None of these

What is the correct answer?

4

All gases above its inversion temperature, in a throttling process will show

A. A heating effect

B. No change in temperature

C. A cooling effect

D. Either (A) or (C)

What is the correct answer?

4

Which of the following is not a reversible process?

A. Expansion of an ideal gas against constant pressure

B. Atmospheric pressure vaporisation of water at 100°C

C. Solution of NaCl in water at 50°C

D. None of these

What is the correct answer?

4

In case of the decomposition of hydroiodic acid (2HI H2 + I2), addition of H2 (at equilibrium condition) will

A. Increase the partial pressure of I2

B. Decrease the partial pressure of HI

C. Diminish the degree of dissociation of HI

D. None of these

What is the correct answer?

4

For a reversible process involving only pressure-volume work

A. (dF)T, p < 0

B. (dF)T, p > 0

C. (dF)T, p = 0

D. (dA)T, v < 0

What is the correct answer?

4

It is desired to bring about a certain change in the state of a system by performing work on the system under adiabatic conditions.

A. The amount of work needed is path dependent

B. Work alone cannot bring out such a change of state

C. The amount of work needed is independent of path

D. More information is needed to conclude anything about the path dependence or otherwise of the work needed

What is the correct answer?

4

The enthalpy change when ammonia gas is dissolved in water is called the heat of

A. Solution

B. Formation

C. Dilution

D. Combustion

What is the correct answer?

4

Law of corresponding states says that

A. Two different gases behave similarly, if their reduced properties (i.e. P, V and T) are same

B. The surface of separation (i. e. the meniscus) between liquid and vapour phase disappears at the critical temperature

C. No gas can be liquefied above the critical temperature, howsoever high the pressure may be.

D. The molar heat of energy of gas at constant volume should be nearly constant (about 3 calories)