Home
Current Affairs January 2024

What is the correct answer?

4

Maxwell's relation corresponding to the identity, dH = dS = Vdp + Σμi dni is

A. (∂T/∂V)S, ni = -(∂P/∂S)V, ni

B. (∂S/∂P)T, ni = (∂V/∂T)P, ni

C. (∂S/∂V)T, ni = (∂P/∂T)V, ni

D. (∂T/∂P)S, ni = (∂V/∂S)P, ni

Correct Answer :

D. (∂T/∂P)S, ni = (∂V/∂S)P, ni


Related Questions

What is the correct answer?

4

Entropy of an ideal gas depends upon its

A. Pressure

B. Temperature

C. Both (A) & (B)

D. Neither (A) nor (B)

What is the correct answer?

4

The rate at which a substance reacts is proportional to its active mass and the rate of a chemical reaction is proportional to the product of active masses of the reacting substances. This is the

A. Lewis-Randall rule

B. Statement of Van't Hoff Equation

C. Le-Chatelier's principle

D. None of these

What is the correct answer?

4

Throttling process is a/an __________ process.

A. Reversible and isothermal

B. Irreversible and constant enthalpy

C. Reversible and constant entropy

D. Reversible and constant enthalpy

What is the correct answer?

4

Work done may be calculated by the expression ∫ p dA for __________ processes.

A. Non-flow reversible

B. Adiabatic

C. Both (A) and (B)

D. Neither (A) nor (B)

What is the correct answer?

4

Which of the following is not a unit of the equilibrium constant Kp? (where, Δx = number of moles of products number of moles of reactants)

A. (atm)Δx, when Δx is negative

B. (atm)Δx, when Δx is positive

C. Dimensionless, when Δx = 0

D. (atm)Δx2, when Δx > 0

What is the correct answer?

4

The Maxwell relation derived from the differential expression for the Helmholtz free energy (dA) is

A. (∂T/∂V)S = - (∂P/∂S)V

B. (∂S/∂P)T = - (∂V/∂T)P

C. (∂V/∂S)P = (∂T/∂P)S

D. (∂S/∂V)T = (∂P/∂T)V

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

The necessary condition for phase equilibrium in a multiphase system of N components is that the

A. Chemical potentials of a given component should be equal in all phases

B. Chemical potentials of all components should be same in a particular phase

C. Sum of the chemical potentials of any given component in all the phases should be the same

D. None of these

What is the correct answer?

4

A reasonably general expression for vapourliquid phase equilibrium at low to moderate pressure is φi yi P = Yi xifi° where, Φ is a vapor fugacity component, Yi is the liquid activity co-efficient and fi° is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of

A. Temperature only

B. Temperature and pressure only

C. Temperature, pressure and liquid composition xi only

D. Temperature, pressure, liquid composition xi and vapour composition yi

What is the correct answer?

4

The work done in an adiabatic change in a particular gas depends upon changes in the __________ only.

A. Temperature

B. Specific heat

C. Volume

D. Pressure

What is the correct answer?

4

A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect?

A. Vapor compression cycle using expansion valve

B. Air refrigeration cycle

C. Vapor compression cycle using expansion engine

D. Carnot refrigeration cycle

What is the correct answer?

4

The theoretical minimum work required to separate one mole of a liquid mixture at 1 atm, containing 50 mole % each of n- heptane and noctane into pure compounds each at 1 atm is

A. -2 RT ln 0.5

B. -RT ln 0.5

C. 0.5 RT

D. 2 RT

What is the correct answer?

4

For a cyclic process, a fixed ratio between heat and work

A. Always exists

B. May exist

C. Never exists

D. Is difficult to predict

What is the correct answer?

4

In case of an __________ process, the temperature of the system increases.

A. Isothermal compression

B. Isothermal expansion

C. Adiabatic expansion

D. Adiabatic compression

What is the correct answer?

4

In an isothermal process on an ideal gas, the pressure increases by 0.5 percent. The volume decreases by about __________ percent.

A. 0.25

B. 0.5

C. 0.75

D. 1

What is the correct answer?

4

The second law of thermodynamics states that

A. The energy change of a system undergoing any reversible process is zero

B. It is not possible to transfer heat from a lower temperature to a higher temperature

C. The total energy of system and surrounding remains the same

D. None of the above

What is the correct answer?

4

The unit of equilibrium constant of a chemical reaction is the same as that of

A. Molar concentration

B. Temperature

C. Internal energy

D. None of these

What is the correct answer?

4

Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in

A. Increased COP

B. Same COP

C. Decreased COP

D. Increased or decreased COP; depending upon the type of refrigerant

What is the correct answer?

4

As the entropy of the universe is increasing, day by day, the work producing capacity of a heat engine is

A. Not changed

B. Decreasing

C. Increasing

D. Data sufficient, can't be predicted

What is the correct answer?

4

In a working refrigerator, the value of COP is always

A. 0

B. < 0

C. < 1

D. > 1

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

Claude gas liquefaction process employs cooling

A. At constant pressure

B. By throttling

C. By expansion in an engine

D. None of these

What is the correct answer?

4

When a system is in equilibrium for all possible processes, the differential or finite change of entropy is

A. < 0

B. > 0

C. = 0

D. None of these

What is the correct answer?

4

Pick out the wrong statement.

A. An ideal liquid or solid solution is defined as one in which each component obeys Raoult's law

B. If Raoult's law is applied to one component of a binary mixture; Henry's law or Raoult's law is applied to the other component also

C. Henry's law is rigorously correct in the limit of infinite dilution

D. None of these

What is the correct answer?

4

Joule-Thomson Co-efficient at any point on the inversion curve is

A.

B. +ve

C. 0

D. -ve

What is the correct answer?

4

Which of the following has the least thermal efficiency?

A. Steam engine

B. Carnot engine

C. Diesel engine

D. Otto engine

What is the correct answer?

4

Extensive properties of a thermodynamic system depend upon the __________ of the system.

A. Specific volume

B. Temperature

C. Mass

D. Pressure

What is the correct answer?

4

Number of components (C), phase (P) and degrees of freedom (F) are related by Gibbs phase rule as

A. P + F - C = 2

B. C = P - F + 2

C. F = C - P - 2

D. P = F - C - 2

What is the correct answer?

4

For a real gas, the chemical potential is given by

A. RT d ln P

B. RT d ln f

C. R d ln f

D. None of these

What is the correct answer?

4

Chemical engineering thermodynamics is concerned with the __________ in/of chemical processes.

A. Reaction mechanism

B. Calculation of rates

C. Energy transformation from one form to another

D. None of these