Partial molar free energy of an element A in solution is same as its (A) Chemical potential
(B) Activity
(C) Fugacity
(D) Activity co-efficient

1 Answer

Answer :

(A) Chemical potential

Related questions

Description : Pick out the wrong statement. (A) Activity co-efficient is dimensionless. (B) In case of an ideal gas, the fugacity is equal to its pressure. (C) In a mixture of ideal gases, the fugacity of ... equal to the partial pressure of the component. (D) The fugacity co-efficient is zero for an ideal gas

Last Answer : (D) The fugacity co-efficient is zero for an ideal gas

Description : Gibbs-Duhem equation relates composition in liquid phase and the __________ at constant temperature & pressure. (A) Fugacity (B) Partial pressure (C) Activity co-efficient (D) All (A), (B), and (C)

Last Answer : (D) All (A), (B), and (C)

Description : For an ideal liquid solution, which of the following is unity? (A) Activity (B) Fugacity (C) Activity co-efficient (D) Fugacity co-efficient

Last Answer : (C) Activity co-efficient

Description : Free energy, fugacity and activity co-efficient are all affected by change in the temperature. The fugacity co-efficient of a gas at constant pressure ____with the increase of reduced temperature. (A) Decreases (B) Increases (C) Remains constant

Last Answer : (B) Increases

Description : Which of the following is not affected by temperature changes? (A) Fugacity (B) Activity co-efficient (C) Free energy (D) None of these

Last Answer : (D) None of these

Description : Which of the following is affected by the temperature? (A) Fugacity (B) Activity co-efficient (C) Free energy (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

Description : In an ideal solution, the activity of a component equals its (A) Mole fraction (B) Fugacity at the same temperature and pressure (C) Partial pressure (D) None of these

Last Answer : (A) Mole fraction

Description : In an ideal gas mixture, fugacity of a species is equal to its (A) Vapor pressure (B) Partial pressure (C) Chemical potential (D) None of these

Last Answer : (B) Partial pressure

Description : Chemical potential (an intensive property) of a substance is a force that drives the chemical system to equilibrium and is equal to its partial molar properties. The ratio of chemical potential to free energy of a pure substance ... temperature and pressure is (A) 0 (B) 1 (C) ∞ (D) None of these

Last Answer : (B) 1

Description : For a multi-component system, the term chemical potential is equivalent to the (A) Molal concentration difference (B) Molar free energy (C) Partial molar free energy (D) Molar free energy change

Last Answer : (C) Partial molar free energy

Description : A reasonably general expression for vapour-liquid phase equilibrium at low to moderate pressure is φi yi P = Yi xifi° where, Φ is a vapor fugacity component, Yiis the liquid activity co- ... and liquid composition xi only (D) Temperature, pressure, liquid composition xi and vapour composition yi

Last Answer : (C) Temperature, pressure and liquid composition xi only

Description : The molar excess Gibbs free energy, gE, for a binary liquid mixture at T and P is given by, (gE/RT) = A . x1. x2, where A is a constant. The corresponding equation for ln y1, where y1is the activity co-efficient of component 1, is (A) A . x22 (B) Ax1 (C) Ax2 (D) Ax12

Last Answer : (A) A . x22

Description : With increase in reduced temperature, the fugacity co-efficient of a gas at constant reduced pressure (A) Increases (B) Decreases (C) Remain same (D) Decreases linearly

Last Answer : (A) Increases

Description : Fugacity of a component in an ideal gas mixture is equal to the partial pressure of that component in the mixture. The fugacity of each component in a stable homogeneous solution at constant pressure and ... increases. (A) Decreases (B) Decreases exponentially (C) Increases (D) Remain constant

Last Answer : (C) Increases

Description : The unit of fugacity is the same as that of the (A) Pressure (B) Temperature (C) Volume (D) Molar concentration

Last Answer : (A) Pressure

Description : For multi-component multiple phases to be in equilibrium at the same pressure and temperature, the __________ of each component must be same in all phases. (A) Chemical potential (B) Fugacity (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Description : When liquid and vapour phases of one component system are in equilibrium (at a given temperature and pressure), the molar free energy is (A) More in vapour phase (B) More in liquid phase (C) Same in both the phases (D) Replaced by chemical potential which is more in vapour phase

Last Answer : (C) Same in both the phases

Description : At equilibrium condition, the chemical potential of a material in different phases in contact with each other is equal. The chemical potential for a real gas (μ) is given by (where, μ = standard chemical potential at unit fugacity (f° = 1 atm. ... (B) μ°+ R ln f (C) μ° + T ln f (D) μ° + R/T ln f

Last Answer : (A) μ° + RT ln f

Description : The chemical potential for a pure substance is __________ its partial molal free energy. (A) More than (B) Less than (C) Equal to (D) Not related to

Last Answer : (C) Equal to

Description : For an ideal solution, the value of activity co-efficient is (A) 0 (B) 1 (C) < 1 (D) > 1

Last Answer : (B) 1

Description : At 60° C, vapour pressure of methanol and water are 84.562 kPa and 19.953 kPa respectively. An aqueous solution of methanol at 60° C exerts a pressure of 39.223 kPa; the liquid phase and vapour phase mole ... respectively. Activity co-efficient of methanol is (A) 1.572 (B) 1.9398 (C) 3.389

Last Answer : (A) 1.572

Description : In a homogeneous solution, the activity co-efficient of a component depends upon the (A) Pressure (B) Composition (C) Temperature (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Activity co-efficient is a measure of the (A) Departure from ideal solution behaviour (B) Departure of gas phase from ideal gas law (C) Vapour pressure of liquid (D) None of these

Last Answer : (A) Departure from ideal solution behaviour

Description : The activity co-efficient of the solute in a dilute solution (A) Decreases with the increase of concentration of the solute (B) Increases with the increase of concentration of the solute (C) Remains constant (D) Is unity at infinite dilution

Last Answer : (C) Remains constant

Description : Out of the following four assumptions used in the derivation of theequation for LMTD [LMTD = (∆t1 - ∆t2 )/ln(∆t1 /∆t2 )], which one is subject to the largest deviation in practice ? (A) Constant ... (B) Constant rate of fluid flow (C) Constant specific heat (D) No partial phase change in the system

Last Answer : (B) Constant rate of fluid flow

Description : The standard state of a gas (at a given temperature) is the state in which fugacity is equal to (A) Unity (B) Activity (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Description : For a given substance at a specified temperature, activity is __________ to fugacity. (A) Directly proportional (B) Inversely proportional (C) Equal (D) None of these

Last Answer : (A) Directly proportional

Description : In a homogeneous solution, the fugacity of a component depends upon the (A) Pressure (B) Composition (C) Temperature (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : The partial molar enthalpy of a component in an ideal binary gas mixture of composition Z, at a temperature T and pressure P, is a function only of (A) T (B) T and P (C) T, P and Z (D) T and Z

Last Answer : (B) T and P

Description : 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

Last Answer : (D) None of these

Description : If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as (A) Solubility increases as temperature ... (D) Solubility increases or decreases with temperature depending on the Gibbs free energy change of solution

Last Answer : (B) Solubility increases as temperature decreases

Description : What is the value of ln y (where y = activity co-efficient) for ideal gases? (A) Zero (B) Unity (C) Infinity (D) Negative

Last Answer : (A) Zero

Description : For an ideal gas, the activity co-efficient is (A) Directly proportional to pressure (B) Inversely proportional to pressure (C) Unity at all pressures (D) None of these

Last Answer : (C) Unity at all pressures

Description : ________ Equation predicts the activity co-efficient from experimental data. (A) Lewis-Randall (B) Margules (C) Van Laar (D) Both (B) & (C)

Last Answer : (D) Both (B) & (C)

Description : Which of the following equations is used for the prediction of activity co-efficient from experiments? (A) Van Laar equation (B) Margules equation (C) Wilson's equation (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Dephosphorization of molten pig iron is favoured by (A) Oxidising and basic slag (B) Reducing and basic slag (C) High activity co-efficient of phosphorous in metal (D) Oxidising and neutral slag

Last Answer : Option B

Description : For a stable phase at constant pressure and temperature, the fugacity of each component in a binary system __________ as its mole fraction increases. (A) Decreases (B) Increases (C) Remain same (D) Decreases linearly

Last Answer : (B) Increases

Description : Fugacity is a measure of the (A) Escaping tendencies of the same substance in different phases of a system (B) Relative volatility of a mixture of two miscible liquids (C) Behaviour of ideal gases (D) None of these

Last Answer : (A) Escaping tendencies of the same substance in different phases of a system

Description : Diffusion co-efficient of a metal in a solid solution depends upon its (A) Composition (B) Temperature (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Description : The overall mass transfer co-efficient for the absorption of SO2 in air with dilute NaOH solution can be increased substantially by (A) Increasing the gas film co-efficient (B) Increasing the liquid film co-efficient (C) Increasing the total pressure (D) Decreasing the total pressure

Last Answer : (A) Increasing the gas film co-efficient

Description : . A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because (A) Total heat transfer area of ... in a single effect is much lower than that in any effect in a multi-effect system

Last Answer : (B) Total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect

Description : Pick out the wrong statement. (A) 'Solvates' are chemical compounds formed by solute with their solvents. When water is the solvent, then it is called a 'hydrate' (B) In heat exchanger ... vertical evaporators, area of central downtake is about 50 to 100% of the total tube cross-sectional area

Last Answer : (C) Heat transfer co-efficient during nucleate boiling is not influenced by the agitation imparted

Description : Superior quality laboratory apparatus is made of the __________ glass having low thermal co-efficient of expansion & high chemical resistance. (A) Flint (B) Soda (C) Pyrex (D) Potash

Last Answer : (C) Pyrex

Description : “The fugacity of a gas in a mixture is equal to the product of its mole fraction and its fugacity in the pure state at the total pressure of the mixture". This is (A) The statement as per Gibbs-Helmholtz (B) Called Lewis-Randall rule (C) Henry's law (D) None of these

Last Answer : (B) Called Lewis-Randall rule

Description : For water at 300°C, it has a vapour pressure 8592.7 kPa and fugacity 6738.9 kPa Under these conditions, one mole of water in liquid phase has a volume of 25.28 cm3 and that in vapour phase in 391.1 cm3.Fugacity of water (in kPa) at 9000 kPa will be (A) 6738.9 (B) 6753.5 (C) 7058.3 (D) 9000

Last Answer : (B) 6753.5

Description : Fugacity and pressure are numerically not equal for the gases (A) At low temperature and high pressure (B) At standard state (C) Both (A) and (B) (D) In ideal state

Last Answer : (C) Both (A) and (B)

Description : Fugacity and pressure are numerically equal, when the gas is (A) In standard state (B) At high pressure (C) At low temperature (D) In ideal state

Last Answer : (D) In ideal state

Description : In an interphase heat transfer process, the equilibrium state corresponds to equality of temperature in the two phases, while the condition for equilibrium in an interphase mass transfer process is ... B) Chemical potentials (C) Activity co-efficients (D) Mass transfer co-efficients

Last Answer : (A) Concentrations

Description : Specific/molar Gibbs free energy for a pure substance does not change during (A) Sublimation (B) Vaporisation (C) Melting (D) Either (A), (B) or (C)

Last Answer : (D) Either (A), (B) or (C)

Description : If the molar heat capacities (Cp or Cv) of the reactants and products of a chemical reaction are identical, then, with the increase in temperature, the heat of reaction will (A) Increase (B) Decrease (C) Remain unaltered (D) Increase or decrease; depends on the particular reaction

Last Answer : (C) Remain unaltered