Prelim Flashcards
The total Gibbs Free Energy for all phases in a multiphase, multicomponent system is
Minimum
The ratio of mole fractions of a species present in liquid-liquid equilibrium
distribution coefficient
For non ideal liquid solutions the model for correlating liquid-phase activity coefficients of binary pairs that uses local area fraction as the primary concentration variable rather than local volume or mole fractions
UNIQUAC
A solution is ideal when activity coefficients are all equal to
1
Fugacity as a substitute for chemical potential in phase equilibria calculations was proposed by
Lewis
For systems in equilibrium, the given species in each existing phase has equality of phase
chemical potential
Graphical correlations of pure component thermodynamic properties are widely available for an solution at near
Ambient Pressure
The approximate expression for estimating K-value for non ideal liquid solutions at moderate pressure and below the critical temperature
Poynting correction
The ratio for the equilibrium ratios for vapor-liquid systems is the
Relative Volatility
For a pure ideal gas, fugacity is equal to
Pressure
Equation that provides the quantitative measure of the thermodynamic inefficiency of the process
Availability Balance
Dissolving pharmaceutical products from bark or roots of plants employs
Leaching
For non ideal vapor and liquid mixtures containing non polar components which of the following equations can be used to estimate activity coefficients, volume and Enthalpy of mixing and K values
SR
PR
LKP
So All of these
The equivalent work of separation for an irreversible process is given by
Lost work + Minimum work
Which of the following describes activity
ratio of partial fugacity of a component to its fugacity in some defined standard state
Which of the following equations of state for non ide vapor and liquid mixtures does not use acentric factor
Redlich-Kwong
For a pure ideal gas, fugacity equals
Total Pressure
Which is true about lost work in a separation operation
the greater its value the greater the energy inefficiency
The simplest model of when both vapor and liquid are ideal solutions and the vapor is an ideal gas applies only at near ambient pressure up to about
50 psia
Which is not true about availability
is conserved in a real irreversible process
Fick’s law of Diffusion is an extension of
Fourier’s Law of heat conduction
Which of the following is not true about binary equimolar counterdiffusion
at constant molar density Dab = - Dba
For equimolar mixture of A and B, in unimolecular diffusion, mass transfer of component A in stagnant B, if 1 - Xa is 0.5, then
NA = 2JA
For estimating the diffusivity in gas mixtures, which of the following equations can be used
Chapman-Enskog Equation
The Nernst-Haskell equation is used to estimating diffusion coefficients of
electrolytes
For steady state, one dimensional molecular diffusion through stationary medium B, with constant DAB, the molar rate of mass transfer of A for plane wall is proportional to, EXCEPT
thickness
( it is proportional to diffusivity, area, and concentration gradient)
The model for mass transfer at fluid-fluid interface most useful when mass transer involves bubbles or droplets or flow over random packing
Penetration theory
The total molar rate of absorption of A through a falling liquid film B is directly proportional to
film thickness
film width
concentration gradient
The mass transfer coefficient for component A is given by
kc = nA/A∆CA
Used to estimate the values of heat and mass transfer coefficients from experimental measurements of the Fanning friction factor for turbulent flow at Npy= Nsc= 1
Reynolds Analogy
