Separation Process

Question 1

The unit operation by which soluble components of a liquid mixture are dissolved in a liquid immiscible with the insoluble component is

Answer 1

Solvent Extraction

Question 2

The most commonly used leaching solvent in the vegetable oil industry

Answer 2

Hexane

Question 3

Leaching of sugar from sugar beets is done using?

Answer 3

Hot water

Question 4

Equipment used for extraction of oil from oilseed

Answer 4

Bollman extractor

Question 5

Radioactive nuclear waste is treated in

Answer 5

Pulsed column extractor

Question 6

Equipment used to process uranium and gold ore (or mineral processing)

Answer 6

Pachuca tanks

Question 7

In a counter-current extractor, as the axial mixing increases, the extraction efficiency

Answer 7

Decreases

Question 8

Acetic acid will be most economically separated from a dilute solution of acetic acid in water by what method?

Answer 8

Solvent Extraction

Question 9

Liquid-liquid extraction is based on the differences in?

Answer 9

Solubility

Question 10

It is a more efficient method of LLE

Answer 10

Repeated small washing

Question 11

The solvent used in liquid extraction should not have a high latent heat of vaporization because?

Answer 11

Its recovery cost by distillation maybe prohibitively high

Question 12

Solvent extraction is the terminology applied to the liquid-liquid extraction, which is preferred for the separation of the components of liquids when

Answer 12

Extracting solvent is cheaply & abundantly available

Question 13

In a counter-current liquid extractor

Answer 13

Only one of the liquids may be pumped at a desired rate

Question 14

Antibiotics are best handled in a?

Answer 14

Podbielniak extractor

Question 15

A solution that follows Raoult’s law most closely

Answer 15

A solution of benzene, toluene, and oxylene

Question 16

Pure liquid is also known as

Answer 16

Subcooled liquid

Question 17

Pure vapor is also known as

Answer 17

Superheated

Question 18

The boiling point diagram is affected by what property?

Answer 18

Pressure

Question 19

The ease of difficulty of separating components by distillation is determined by the

Answer 19

Relative volatility

Question 20

The relative volatility of most ideal binary solutions is greatly affected by what property?

Answer 20

Temperature

Question 21

When the relative volatility of two miscible components is close to 1, it can be separated by

Answer 21

Extractive distillation

Question 22

The physical separation of components in a miscible mixture by simultaneous evaporation and condensation is

Answer 22

Distillation

Question 23

In batch distillation, the boiling point of the distillate product compared to the residue is?

Answer 23

Lower

Question 24

Increasing the operating pressure of a distilling column affects separation in what way?

Answer 24

Makes separation difficult

Question 25

One mol feed of a binary mixture of a given composition is flash vaporized at a fixed T and P. If Raoult's Law is obeyed, then changing the feed composition would affect

Answer 25

The fraction vaporized but not the product composition

Question 26

Steam distillation is used to

Answer 26

Avoid thermal decomposition of a component

Question 27

The amount of steam required per unit quantity of distillate in case of steam distillation will be reduced by what method?

Answer 27

By raising the temp and lowering the total pressure

Question 28

In distillation, the cooled liquid stream returned to the column to a cool plate stage is called

Answer 28

Reflux

Question 29

In distilling column, the highest pressure will be at the?

Answer 29

Bottom

Question 30

A heat transfer equipment used to convert vapor to liquid

Answer 30

Condenser

Question 31

A reboiler provides heat to the

Answer 31

Bottom of the distilling column

Question 32

The temperature in a distilling column, from bottom to top (increases or decreases)?

Answer 32

Decreases

Question 33

Rose oil is extracted from rose leaves using ___ distillation

Answer 33

Steam distillation

Question 34

When the solvent dissolves very little solute then

Answer 34

A large quantity of solvent is required to extract the solute

Question 35

An ideal single-stage extraction process is used to treat 100 mol/s of an organic feed solution. The solute concentration in this solution is reduced from 0.5 mol % to 0.1 mol %. A pure solvent S is used. To reduce the solvent requirement by half for the same separation

Answer 35

Use another pure solvent S* whose partition coefficient is twice that of S

Question 36

The triangle whose one corner coincides with the enriching line and the outer corner is on the stripping line is called the

Answer 36

Feed plate

Question 37

Flash distillation is suitable for the separation of what kind of components?

Answer 37

Components with very wide boiling points

Question 38

Relative volatility varies with the concentration of components for an ideal solution. The relative volatility of a binary mixture may be defined as the ratio of vapor component 'A' to that of component 'B' when

Answer 38

Vapor phase obeys Dalton's law and liquid phase obeys Raoult's law

Question 39

Leaching of coarse solid lumps is also termed as

Answer 39

Percolation

Question 40

Large scale usage of flash distillation is practiced in what industry?

Answer 40

Petroleum Refining

Question 41

In an operating distillation column, the

Answer 41

Driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from the bottom to the top of the column

Question 42

In case of steam distillation, the steam leaving the liquid is not completely saturated with distillate vapor, because

Answer 42

Mixing of steam with the material being vaporized is not so intimate as to result in equilibrium condition

Question 43

For a binary mixture distillation process, the degree of freedom is 2. However, if the pressure is fixed in this process, the number of independent variables in this process will be

Answer 43

1

Question 44

The theoretical minimum reflux ratio in the distillation column is attained if the column has

Answer 44

Infinite number of plates

Question 45

Leaching Perry's Chapter

Answer 45

18

Question 46

LLE Perry's Chapter

Answer 46

15

Question 47

Distillation Perry's Chapter

Answer 47

13

Question 48

Alternative Separation Process Chapter sa Handbook

Answer 48

20

Question 49

Fenske's equation for determining the minimum number of theoretical stages in distillation column holds good, when the a. relative volatility is reasonably constant. b. mixture (to be separated) shows negative deviation from ideality. c. mixture (to be separated) shows positive deviation from ideality. d. multicomponent distillation is involved.

Answer 49

A.

Question 50

In a distillation column, with increase in the reflux ratio, the heat removed in the cooler

Answer 50

Increases

Question 51

Inside the distillation column, the a. driving force for the vapor flow is the pressure drop. b. liquids are not always at their bubble points. c. pressure increases gradually from bottom to the top of the column. d. none of these

Answer 51

A.

Question 52

On moving the feed line (q-line) from saturated liquid feed (vertical position) to saturated vapor feed (horizontal feed), if the slope of both the operating lines are to be increased, then it will result in a. greater degree of separation with a fixed number of trays b. increased reboiler load c. increased reflux ratio d. none of these

Answer 52

C.

Question 53

In case of binary distillation, increasing the reflux ratio above optimum does not result in the increase of a. area between operating line and 45° diagonal x-y diagram b. condenser and reboiler surfaces c. tower cross-section d. none of these

Answer 53

A.

Question 54

In case of binary distillation, increasing the reflux ratio above optimum does not result in the increase of a. area between operating line and 45° diagonal x-y diagram b. condenser and reboiler surfaces c. tower cross-section d. none of these

Answer 54

A.

Question 55

Overall efficiency of the distillation column is

Answer 55

the ratio of number of ideal plates to actual plates

Question 56

Pick out the correct statement. a. Ponchon-Savarit method is more accurate than McCabe- Thiele method to determine the number of theoretical stages required for the separation of non-ideal binary system by distillation. b. A sharp decrease in pressure drop is an indication of flooding in a distillation column. c. Solvent used in extractive distillation should be of high volatility. d. Flash distillation is suitable for separating components which have very close boiling temperature.

Answer 56

A.

Question 57

Pick out the correct statement. a. The slope of the stripping line is always less than unity. b. For a given separation in a binary distillation column, with increase in reflux ratio (above the minimum reflux ratio), the fixed cost of the distillation column first increases and then decreases. c. In Ponchon-Savarit method of no. of theoretical plate determination, the stripping and rectifying operating lines are vertical at total reflux. d. Kremsor-Brown-Souder's equation is used to calculate the efficiency of a plate tower.

Answer 57

C.

Question 58

Design calculation for multiple component distillation is done by

Answer 58

tray to tray calculations

Question 59

Pick out the wrong statement: a. Reboiler is not used in open steam distillation. b. The separation of solutes of different molecular sizes in a liquid solution by use of a suitable membrane is called dialysis. c. Freeze drying is used for the drying of fish. d. Fenske-Underwood equation is used for calculating theoretical number of plates in a distillation column at normal operating reflux condition.

Answer 59

D.

Question 60

In extractive distillation, solvent is

Answer 60

added to alter the relative volatility of the mixture

Question 61

Solvent used in extractive distillation a. is of low volatility. b. forms a low boiling azeotrope. c. forms a high boiling azeotrope. d. does not alter the relative volatility of the original components

Answer 61

B.

Question 62

Pick out the wrong statement. a. Critical moisture content is not a property of the material itself. b. A sharp increase in pressure drop gives an indication of the flooding in a distillation column. c. Separation of components is not possible in liquid extraction, if selectivity is unity. d. Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum.

Answer 62

D.

Question 63

Azeotropic distillation is employed to separate

Answer 63

Constant boiling mixture

Question 64

The equilibrium liquid composition compared to the vapor composition in case of azeotropic mixture is

Answer 64

Same

Question 65

Pick out the wrong statement. a. The mole fraction of solute is directly proportional to the molality of a 'dilute' solution. b. For a non-reacting binary mixture of ideal gases, the partial pressure distribution of both components is nonlinear in the case of steady state unimolal unidirectional diffusion. c. Azeotropes obey Raoult's law at all temperature. d. The relative volatility of a binary mixture at the azeotropic composition is 1.

Answer 65

C.

Question 66

Pick out the system with minimum boiling azeotrope at 1 atm. a. benzene-toluene c. hydrochloric acid-water b. ethyl alcohol-water d. all of these

Answer 66

C.

Question 67

Which of the following binary systems is an example of a maximum boiling azeotrope? a. water-hydrochloric acid b. acetone-carbon disulfide c. water-ethyl alcohol d. n-heptane-n-octane

Answer 67

C.