PrepBharat

1. Which model is used for predicting liquid-phase activity coefficients?
a) Entropy models
b) Enthalpy models
c) Gibb’s free equation model
d) Keller model

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2. The relationship between excess molar free energy and excess molar enthalpy is:
a) G^E = h^E – TS^E
b) G^E = h^E + TS^E
c) G^E = – TS^E
d) G^E = h^E – T

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3. For a regular solution model what is the excess molar free enrgy dependent upon?
a) Volume occupied by molecules
b) Interaction of molecules
c) Molecular size and intermolecular forces
d) Enthalpy of formation of molecules

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4. Non-ideal solution effects can be incorporated in K-value formulations by:
a) Integrating for each molecule
b) Use of excess free energy
c) Use of enthalpy of vaporization
d) Use of partial fugacity coefficient ϕ_i

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5. In Margules equation, what is the one constant form equivalent to?
a) Unsymmetrical activity coefficient curves
b) Symmetrical activity coefficient curves
c) Similar partial fugacity coefficients
d) Dissimilar partial fugacity coefficients

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6. What is the temperature dependence of van laar constant?
a) A_ij = A’_ij/T
b) A_ij = A’_ijR/T
c) A_ij = A’_ij/TR
d) A_ij = A’_ij*RT

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7. When is Wilson’s equation superior to Margules and Van laar equation?
a) Non-ideal and immiscible mixtures
b) Ideal and miscible mixtures
c) Non-ideal and miscible mixtures
d) Ideal and immiscible mixtures.

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8. What is the full form of NRTL model?
a) No rational two liquid model
b) Non-random three liquid model
c) Non-random two liquid model
d) Non-Rating two liquid model

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9. How does the UNIQUAC model help?
a) It helps to place calculations of activity coefficients on practical basis
b) It helps to place calculations of activity coefficients on theoretical basis
c) It helps to place calculations of activity coefficients from graph
d) It helps to provide a easier way to place calculations

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10. What must be true for two coexisting liquid phases?
a) Y_iL⁽¹⁾x_i⁽¹⁾ = Y_iL⁽²⁾x_i⁽²⁾
b) Y_iL⁽¹⁾x_i⁽¹⁾ = x_i⁽²⁾
c) Y_iL⁽¹⁾x_i⁽¹⁾= Y_iL⁽²⁾y_i⁽²⁾
d) Y_iL⁽¹⁾x_i⁽¹⁾ = X_iL⁽²⁾x_i⁽²⁾

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