The value of L/mG ratio for economical absorption operation ranges from

The Knudsen diffusivity is dependent on the

Co-current absorbers are usually used when the gas to be dissolved in the liquid is

At what percentage (by volume) of alcohol composition, it forms an azeotrope with water ?

Mass transfer co-efficient is defined as

Which of the following is not a continuous drier ?

Condensation of a vapour-gas mixture just begins, when (where, p = partial pressure of the vapour P = vapour pressure of the liquid )

Flooding in a vapor-liquid contacting equipment occurs in a tray, when the pressure drop through a tray is __________ the liquid head available in the downcomer.

Milk is dried usually in a __________ dryer.

The equation, is for

In case of absorption & stripping, the interface of the liquid & gas phases are present in equilibrium, when the diffusional resistance of __________ is zero.

Which one of the following devices is not used for both the absorption as well as the liquid-liquid extraction processes ?

Can the efficiency of a plate in the distillation tower be greater than?

In extractive distillation, solvent is

For a binary mixture distillation process, the degree of freedom isHowever, if the pressure is fixed in this process, the number of independent variables in this process will be

H₂S is being absorbed in a gas absorber unit. The height of the transfer unit based on the overall mass transfer coefficient on the gas side is 0.4 m. The equilibrium data is given by, y = 1.5 x. The bulk concentration of H₂S has to be reduced from 0.to 0.mole fraction in the gas side. The height of the tower (in metres) corresponding to an operating line given by, y =+ 0.is

The Reynolds number of the liquid was increasedfold for a laminar falling film used for gas-liquid contacting. Assuming penetrating theory is applicable, the fold increase in the mass transfer co-efficient (K_c) for the same sytem is

The slope of 9-line is determined by the

With increase in temperature, the rate of extraction in leaching (solid-liquid extraction system)

With increase in temperature, the leaching rate increases due to

Which of the following processes is not an example of adsorption applied to gaseous separations ?

Pick out the correct relationship. (where, R_i = internal reflux ratio R_o = external reflux ratio. )

The operating cost of a distillation column at minimum reflux ratio is

Polar organic compounds are normally used as separating agents for the azeotropic and extractive distillation. Which of the following is the most important factor to be considered for the choice of the separating agent for extractive distillation ?

If f is defined as above, then which of the following applies to a feed at dew point ?

According to the Fenske equation, what will be the minimum number of plates required in a distillation column to separate an equimolar binary mixture of components A and B into an overhead fraction containingmol% A and a bottom fraction containingmol% B ? Assume that relative volatility (α_AB =does not change appreciably in the coloumn.

The interfacial area per unit volume of dispersion, in a gas-liquid contactor, for fractional hold up of gas = 0.1 and gas bubble diameter = 0.5 mm is given by (in m²/m³)

Large scale usage of flash distillation is practised in

When an unsaturated air-water mixture is heated at constant pressure, then

Pick out the wrong statement pertaining to the analogy between equations of heat and mass transfer operations.

The temperature of water cooled in cooling tower is always __________ temperature of entering air.

If f is defined as above, then which of the following applies to a feed at dew point ?

With increase in the mass velocity of the gas, the rate of drying during the constant rate period __________ , if the conduction and radiation through the solid are negligible.

Which of the following is directly concerned with psychrometry ?

Packed column distillation is limited to the column __________ metres.

The relative volatility of a binary mixture at constant temperature __________ the total pressure.

In steam distillation, the

The critical moisture content in case of drying indicates the __________ rate period.

The reflux to a distillation column ismoles/hr, when the overhead product rate ismoles/hr. The reflux ratio is

As the reflux ratio increases, the slope of the operating line for rectifying section

Absorption (liquid-gas system) with evolution of heat as compared to isothermal absorption results in

Though, theoretically the adsorption & desorption isotherms is expected to coincide but sometimes at least a part of the isotherms does not coincide and this phenomenon is known as adsorption hysterisis. In such cases, the desorption equilibrium pressure is __________ that obtained for adsorption.

During sensible cooling process

The slope of the operating line for a single component co-current absorber when plotted in terms of mole ratio units is

Which of the following processes is followed by unsaturated air (with dry bulb temperature 12°C and relative humidity 47%) passing through water spray washer (temperature of water being constant at 40°C?

Which of the following parameters remains constant during chemical dehumidifica-tion?

Pick out the wrong statement.

For gas absorption, low viscosity solvents are preferred, because of their

The equation, is for

Plate efficiency in a distillation column is reduced due to the __________ of liquid.