The standard Gibbs free energy change of a reaction depends on the equilibrium
(A) Pressure
(B) Temperature
(C) Composition
(D) All (A), (B) and (C)

1 Answer

Answer :

(B) Temperature

Related questions

Description : Gibbs free energy at constant pressure and temperature under equilibrium conditions is (A) ∞ (B) 0 (C) Maximum (D) Minimum

Last Answer : (D) Minimum

Description : In which of the following reactions, standard reaction entropy change (S°) is positive and standard Gibb's energy change (G°) decreases sharply with increasing temperature? (1) 2 2 1 1 1 C graphite O (g) CO (g) 2 2 2   (2) 2 1 C ... CO(g) O (g) CO (g) 2   (4) 2 1 Mg(s) O (g) MgO(s) 2  

Last Answer : C graphite O (g) CO(g)

Description : Gibbs-Duhem equation (A) States that n1dμ1 + n2dμ2 + ....njdμj = 0, for a system of definite composition at constant temperature and pressure (B) Applies only to binary systems (C) Finds no application in gas-liquid equilibria involved in distillation (D) None of these

Last Answer : (A) States that n1dμ1 + n2dμ2 + ....njdμj = 0, for a system of definite composition at constant temperature and pressure

Description : The relation connecting the fugacities of various components in a solution with one another and to composition at constant temperature and pressure is called the __________ equation. (A) Gibbs-Duhem (B) Van Laar (C) Gibbs-Helmholtz (D) Margules

Last Answer : (A) Gibbs-Duhem

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 : Variation of equilibrium pressure with temperature for any two phases of a given substances is given by the __________ equation. (A) Gibbs-Duhem (B) Maxwell's (C) Clapeyron (D) None of these

Last Answer : (C) Clapeyron

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 : Pick out the correct statement. (A) A catalyst speeds up the forward reaction but slows shown the reverse reaction (B) Addition of catalyst changes the equilibrium constant (C) Pressure changes do not change the equilibrium concentrations (D) The composition of equilibrium is changed by catalyst

Last Answer : (C) Pressure changes do not change the equilibrium concentrations

Description : Pick out the wrong statement. (A) Use of different catalysts in a reversible catalytic chemical reaction does not change the equilibrium composition (B) Alumina is added as a promoter to ... Arrhenius plot (D) Presence of inerts affects the equilibrium conversion of reactants in a chemical reaction

Last Answer : (C) Activation energy for a reaction is obtained from the intercept of the Arrhenius plot

Description : 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

Last Answer : (B) Minus infinity

Description : Gibbs free energy of mixing at constant pressure and temperature is always (A) 0 (B) ∞ (C) + ve (D) - ve

Last Answer : (D) - ve

Description : Specific __________ does not change during phase change at constant temperature and pressure. (A) Entropy (B) Gibbs energy (C) Internal energy (D) Enthalpy

Last Answer : (B) Gibbs energy

Description : Chemical reaction rate of a component depends upon the (A) Composition of the component only (B) Temperature of the system (C) Pressure of the system (D) All (A), (B) and (C)

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

Description : In the gaseous phase ammonia formation reaction (N2 + 3H2 ⇌ 2NH3 ), the value of the equilibrium constant depends on the (A) Total pressure of the system (B) Volume of the reactor (C) Temperature (D) Initial concentration of N2 and H2

Last Answer : (C) Temperature

Description : The equilibrium constant ‘K’ of a chemical reaction depends on (A) Temperature only (B) Pressure only (C) Temperature and pressure (D) Ratio of reactants

Last Answer : (A) Temperature only

Description : Pick out the wrong statement. (A) The conversion for a gas phase reaction increases with decrease in pressure, if there is an increase in volume accompanying the reaction (B) With ... phase reaction increases with increase in pressure, if there is a decrease in volume accompanying the reaction

Last Answer : (B) With increase in temperature, the equilibrium constant increases for an exothermic reaction

Description : Assertion :- Catalyst change Gibbs free energy of system. Reason :- Catalyst changes preexponential factor of a chemical reaction.

Last Answer : Assertion :- Catalyst change Gibbs free energy of system. Reason :- Catalyst changes preexponential factor ... . If both Assertion & Reason are false.

Description : The Gibbs free energy change of a reaction at `27^(@)C` is -26 Kcal. and its entropy change is -60 Cals/K. `Delta H` for the reaction is :-

Last Answer : The Gibbs free energy change of a reaction at `27^(@)C` is -26 Kcal. and its entropy change is -60 Cals/K. ... Cals. C. 34 K. Cals. D. `-24` K. Cals.

Description : The equilibrium liquid composition compared to the vapor composition in case of Azeotropic mixture is (A) More (B) Less (C) Same (D) Either more or less; depends on the system

Last Answer : (C) Same

Description : When a gas is expanded from high pressure region to low pressure region; temperature change occurs". This phenomenon is related to the (A) Gibbs-Duhem equation (B) Gibbs-Helmholtz equation (C) Third law of thermodynamics (D) Joule-Thomson effect

Last Answer : (D) Joule-Thomson effect

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 : Boiling of liquid is accompanied with increase in the (A) Vapor pressure (B) Specific Gibbs free energy (C) Specific entropy (D) All (A), (B) and (C)

Last Answer : (A) Vapor pressure

Description : (∂H/∂T)P is the mathematical expression for (A) CV (B) Entropy change (C) Gibbs free energy (D) None of these

Last Answer : (D) None of these

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 : The change in Gibbs free energy for vaporisation of a pure substance is (A) Positive (B) Negative (C) Zero (D) May be positive or negative

Last Answer : (C) Zero

Description : Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.). (A) Entropy (B) Internal energy (C) Enthalpy (D) Gibbs free energy

Last Answer : (D) Gibbs free energy

Description : The change in __________ is equal to the reversible work for compression in steady state flow process under isothermal condition. (A) Internal energy (B) Enthalpy (C) Gibbs free energy (D) Helmholtz free energy

Last Answer : (C) Gibbs free energy

Description : _________ does not change during phase transformation processes like sublimation, melting & vaporisation. (A) Entropy (B) Gibbs free energy (C) Internal energy (D) All (A), (B) & (C)

Last Answer : (B) Gibbs free energy

Description : If a reaction has an enthalpy of -54.32 kJ/mol and an entropy of -354.2 J/(K*mol), what is the Gibbs free Energy at 54.3(degrees c)?

Last Answer : DeltaG = DeltaH - TDeltaS dG = -54.32 kJ/mol - (54'32+273)K(-354.2J/molK) NB Thevtemperature is quoted in Kelvin(K) and the Entropy must be converted to kJ by dividing by '1000'/ Hence dG = ... 115.94 kJ/mol dG = (+)61.61 kJ/mol Since dG is positive, the reaction is NOT thermodynamically feasible.

Description : A system is in ______ equilibrium of its chemical composition does not change with time, i.e., no chemical reaction occurs.  A. Chemical  B. Thermal  C. Mechanical  D. Phase

Last Answer : Chemical

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 : The chemical potential of any constituent of an ideal solution depends on the __________ of the solution. (A) Temperature (B) Pressure (C) Composition (D) All (A), (B) and (C)

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

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 : Pick out the wrong statement. (A) A catalyst does not alter the final position of equilibrium in a reversible reaction (B) A catalyst initiates a reaction (C) A catalyst is specific in reaction (D) A catalyst remains unchanged in chemical composition at the end the reaction

Last Answer : (B) A catalyst initiates a reaction

Description : Bound moisture is that liquid which exerts an equilibrium vapor pressure __________ that of the pure liquid at the given temperature. (A) Less than (B) More than (C) Equal to (D) Either (A) or (B); depends on the solid

Last Answer : (A) Less than

Description : With the lowering of equilibrium pressure, at a given temperature, the amount of adsorbate on the adsorbent (A) Increases (B) Decreases (C) Remain same (D) Either (A) or (B), depends on the system

Last Answer : (B) Decreases

Description : Equation which relates pressure, volume and temperature of a gas is called the (A) Equation of state (B) Gibbs Duhem equation (C) Ideal gas equation (D) None of these

Last Answer : (A) Equation of state

Description : In Azeotropic mixture, the equilibrium vapour composition is (A) More than liquid composition (B) Less than liquid composition (C) Same as liquid composition (D) Independent of pressure

Last Answer : (C) Same as liquid composition

Description : In any spontaneous process, the __________ free energy decreases. (A) Helmholtz (B) Gibbs (C) Both ‘a’ & ‘b’ (D) Neither 'a' nor 'b'

Last Answer : (C) Both ‘a’ & ‘b’

Description : Gibbs free energy per mole for a pure substance is equal to the (A) Latent heat of vaporisation (B) Chemical potential (C) Molal boiling point (D) Heat capacity

Last Answer : (B) Chemical potential

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 : Gibbs free energy (G) is represented by, G = H - TS, whereas Helmholtz free energy, (A) is given by, A = E - TS. Which of the following is the Gibbs Helmholtz equation? (A) [∂(G/T)/∂T] = - (H/T2) (B) [∂(A/T)/∂T]V = - E/T2 (C) Both (A) and (B) (D) Neither (A) nor (B)

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

Description : The free energy change, AG (A) Is directly proportional to the standard free energy change, AG (B) Is equal to zero at equilibrium (C) Can only be calculated when the reactants and products are present at 1mol/1 concentrations (D) Is equal to –RT in keq

Last Answer : B

Description : Higher free energy of activation of a chemical reaction (at a given temperature) implies (A) Slower rate of reaction (B) Higher rate of reaction (C) Higher equilibrium conversion (D) Both (B) and (C)

Last Answer : (A) Slower rate of reaction

Description : The free energy change for a chemical reaction is given by (where, K = equilibrium constant) (A) RT ln K (B) -RT ln K (C) -R ln K (D) T ln K

Last Answer : (B) -RT ln K

Description : The equilibrium constant of chemical reaction __________ in the presence of catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Can either increase or decrease (depends on the type of catalyst)

Last Answer : (C) Remain unaffected

Description : With increase in temperature, the thermal conductivity of fresh lubricating oil (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on its composition

Last Answer : (B) Decreases

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 : 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 : 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