Distillation at reduced pressure is used for liquids which (a) Have high boiling points (b) Have low boiling points (c) Have high volatility (d) Decompose before their boiling points

Distillation at reduced pressure is used for liquids which (a) Have high boiling points (b) Have low boiling points (c) Have high volatility (d) Decompose before their boiling points
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Steam distillation is not recommended to be used, if the (A) Azeotropic mixture is to be separated and the final product is miscible with water (B) Liquids decompose, if distilled directly at atmospheric pressure (C) Material cannot be distilled by indirect heating even under low pressure, because of the high boiling temperature (D) Material to be distilled is thermally unstable or has the tendency to react with other components associated with it, at the boiling temperature

Description : Steam distillation is not recommended to be used, if the (A) Azeotropic mixture is to be separated and the final product is miscible with water (B) Liquids decompose, if ... unstable or has the tendency to react with other components associated with it, at the boiling temperature

Last Answer : (A) Azeotropic mixture is to be separated and the final product is miscible with water

Crude oil is subjected to vacuum distillation in the last stage, because (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose (B) Lighter/low boiling products are prone to thermal decomposition (C) High purity products can be obtained thereby (D) None of these

Description : Crude oil is subjected to vacuum distillation in the last stage, because (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose (B) Lighter/low ... prone to thermal decomposition (C) High purity products can be obtained thereby (D) None of these

Last Answer : (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose

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

Description : 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

Last Answer : (B) Forms a low boiling azeotrope

Entrainer used in Azeotropic distillation should (A) Form a low boiling azeotrope with one of the constituents of the mixture (B) Form a new azeotrope of low relative volatility with one of the constituents of the mixture (C) Have high latent heat of vaporisation (D) Have high viscosity to provide high tray efficiency

Description : Entrainer used in Azeotropic distillation should (A) Form a low boiling azeotrope with one of the constituents of the mixture (B) Form a new azeotrope of low relative volatility with one of the ... (C) Have high latent heat of vaporisation (D) Have high viscosity to provide high tray efficiency

Last Answer : (A) Form a low boiling azeotrope with one of the constituents of the mixture

Pick out the correct statement. (A) Ponchan-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 coloumn (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

Description : Pick out the correct statement. (A) Ponchan-Savarit method is more accurate than McCabe-Thiele method to determine the number of theoretical stages required for the separation of ... Flash distillation is suitable for separating components which have very close boiling temperature

Last Answer : (A) Ponchan-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

Separation of two volatile liquids by distillation makes use of their (A) Selectivity (B) Relative volatility (C) Solubility (D) Density difference

Description : Separation of two volatile liquids by distillation makes use of their (A) Selectivity (B) Relative volatility (C) Solubility (D) Density difference

Last Answer : (B) Relative volatility

For a binary mixture with low relative volatility, (A) Use steam distillation (B) Use molecular distillation (C) Use high pressure distillation (D) An azeotrope may be formed during distillation

Description : For a binary mixture with low relative volatility, (A) Use steam distillation (B) Use molecular distillation (C) Use high pressure distillation (D) An azeotrope may be formed during distillation

Last Answer : (D) An azeotrope may be formed during distillation

The solvent used in liquid extraction should not have high latent heat of vaporisation, because (A) The pressure drop and hence the pumping cost will be very high (B) It cannot be recovered by distillation (C) Its recovery cost by distillation may be prohibitively high (D) It will decompose while recovering by distillation

Description : The solvent used in liquid extraction should not have high latent heat of vaporisation, because (A) The pressure drop and hence the pumping cost will be very high (B) It cannot ... by distillation may be prohibitively high (D) It will decompose while recovering by distillation

Last Answer : (C) Its recovery cost by distillation may be prohibitively high

Inside the distillation column, the (A) Driving force for the vapour 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

Description : Inside the distillation column, the (A) Driving force for the vapour 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

Last Answer : (A) Driving force for the vapour flow is the pressure drop

High pressure at the bottom of a distillation tower handling heat sensitive materials results in (A) Thermal decomposition of bottoms (B) Increased relative volatility (C) Erosion of the tower (D) Very efficient operation

Description : High pressure at the bottom of a distillation tower handling heat sensitive materials results in (A) Thermal decomposition of bottoms (B) Increased relative volatility (C) Erosion of the tower (D) Very efficient operation

Last Answer : (A) Thermal decomposition of bottoms

Two liquids (A)and(B)are separated by fractional distillation, the boiling point of (A) is less than (B).which liquid comes out first in distillate? Explain.

Description : Two liquids (A)and(B)are separated by fractional distillation, the boiling point of (A) is less than (B).which liquid comes out first in distillate? Explain.

Last Answer : The liquid (a) comes out first in distillate. On boiling the vapours of lower boiling component are formed first.

The noble gases have low boiling points because: w) their ionization potentials are very low x) only weak Van der Waals forces hold the atoms together y) they are produced by the fractional distillation of liquid air z) they have eight electrons in the outer shell

Description : The noble gases have low boiling points because: w) their ionization potentials are very low x) only weak Van der Waals forces hold the atoms together y) they are produced by the fractional distillation of liquid air z) they have eight electrons in the outer shell

Last Answer : ANSWER: X -- ONLY WEAK VAN DER WAALS FORCES HOLD THE ATOMS TOGETHER

Pick out the wrong statement. (A) Constant pressure distillation cannot separate an Azeotropic mixture (B) Relative volatility of a binary mixture changes appreciably with the minor change in temperature (C) The relative volatility of a binary mixture at Azeotropic composition is unity (D) Flash distillation is practised on wide spread scale in petroleum refinery

Description : Pick out the wrong statement. (A) Constant pressure distillation cannot separate an Azeotropic mixture (B) Relative volatility of a binary mixture changes appreciably with the minor change in ... unity (D) Flash distillation is practised on wide spread scale in petroleum refinery

Last Answer : (B) Relative volatility of a binary mixture changes appreciably with the minor change in temperature

Solvent used in extractive distillation (A) Changes the relative volatility of the original components (B) Should be of high volatility (C) Should form azeotropes with the original components (D) All (A), (B) and (C)

Description : Solvent used in extractive distillation (A) Changes the relative volatility of the original components (B) Should be of high volatility (C) Should form azeotropes with the original components (D) All (A), (B) and (C)

Last Answer : (A) Changes the relative volatility of the original components

In extractive distillation, solvent is (A) Added to alter the relative volatility of the mixture (B) Of high volatility (C) Present in overhead stream (D) Of high viscosity to give high tray efficiency

Description : In extractive distillation, solvent is (A) Added to alter the relative volatility of the mixture (B) Of high volatility (C) Present in overhead stream (D) Of high viscosity to give high tray efficiency

Last Answer : (A) Added to alter the relative volatility of the mixture

The distillation carried out in such a way that the liquid with the lowest boiling point is first evaporated and recondensed, then the liquid with the next higher boiling point is then evaporated and recondensed, and so on until all the available liquid fuels are separately recovered in the sequence of their boiling points. Such a process is called  A. cracking  B. carbonisation  C. fractional distillation  D. full distillation

Description : The distillation carried out in such a way that the liquid with the lowest boiling point is first evaporated and recondensed, then the liquid with the next higher boiling point is then evaporated and ... is called  A. cracking  B. carbonisation  C. fractional distillation  D. full distillation

Last Answer : Answer: C

Fugacity is a measure of the (A) Escaping tendencies of the same substance in different phases of a system (B) Relative volatility of a mixture of two miscible liquids (C) Behaviour of ideal gases (D) None of these

Description : Fugacity is a measure of the (A) Escaping tendencies of the same substance in different phases of a system (B) Relative volatility of a mixture of two miscible liquids (C) Behaviour of ideal gases (D) None of these

Last Answer : (A) Escaping tendencies of the same substance in different phases of a system

In an operating distillation column, the (A) Vapors and liquids are at their dew point and bubble point respectively (B) Driving force for the liquid flow is its specific weight (C) Driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from the bottom to the top of the column (D) Highest temperature is encountered at the top of the column

Description : In an operating distillation column, the (A) Vapors and liquids are at their dew point and bubble point respectively (B) Driving force for the liquid flow is its specific weight (C) Driving force for ... bottom to the top of the column (D) Highest temperature is encountered at the top of the column

Last Answer : (C) Driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from the bottom to the top of the column

Fenske-Underwood equation used for calculating the minimum number of theoretical plates in distillation column is valid for (A) Constant molal overflow (B) Total reflux (C) Constant relative volatility (D) All (A), (B) and (C)

Description : Fenske-Underwood equation used for calculating the minimum number of theoretical plates in distillation column is valid for (A) Constant molal overflow (B) Total reflux (C) Constant relative volatility (D) All (A), (B) and (C)

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

The-relative volatility for separation of a non-ideal binary mixture by distillation should be (A) 0 (B) 1 (C) > 1 (D) < 1

Description : The-relative volatility for separation of a non-ideal binary mixture by distillation should be (A) 0 (B) 1 (C) > 1 (D) < 1

Last Answer : (C) > 1

If the amount of the steam used in steam distillation is increased, the temperature of distillation (A) Increases (B) Decreases (C) Remains unchanged (D) Depends on relative volatility

Description : If the amount of the steam used in steam distillation is increased, the temperature of distillation (A) Increases (B) Decreases (C) Remains unchanged (D) Depends on relative volatility

Last Answer : (B) Decreases

Fenske 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) Multi-component distillation is involved

Description : Fenske 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) ... (to be separated) shows positive deviation from ideality (D) Multi-component distillation is involved

Last Answer : (A) Relative volatility is reasonably constant

In case of __________ distillation, a solvent is added to alter the relative volatility of the mixture to be separated. (A) Molecular (B) Azeotropic (C) Extractive

Description : In case of __________ distillation, a solvent is added to alter the relative volatility of the mixture to be separated. (A) Molecular (B) Azeotropic (C) Extractive

Last Answer : (C) Extractive

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 containing 99 mol% A and a bottom fraction containing 98 mol% B ? Assume that relative volatility (αAB = 2) does not change appreciably in the column. (A) 5 (B) 9 (C) 12 (D) 28

Description : 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 containing 99 mol% A and a ... in the column. (A) 5 (B) 9 (C) 12 (D) 28

Last Answer : (C) 12

Products drawn from the top to bottom of the crude oil distillation column has progressively increasing (A) Boiling points (B) Molecular weight (C) C/H ratio (D) All (A), (B) and (C)

Description : Products drawn from the top to bottom of the crude oil distillation column has progressively increasing (A) Boiling points (B) Molecular weight (C) C/H ratio (D) All (A), (B) and (C)

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

Flash distillation is suitable for separating the constituents of a binary system, which (A) Form minimum boiling azeotrope (B) Have very wide boiling points (C) Have very close boiling points (D) Form constant boiling azeotrope

Description : Flash distillation is suitable for separating the constituents of a binary system, which (A) Form minimum boiling azeotrope (B) Have very wide boiling points (C) Have very close boiling points (D) Form constant boiling azeotrope

Last Answer : (B) Have very wide boiling points

Flash distillation is suitable for the separation of components (A) Having very close boiling points (B) Which form maximum boiling azeotrope (C) Having very wide boiling points (D) Which form minimum boiling azeotrope

Description : Flash distillation is suitable for the separation of components (A) Having very close boiling points (B) Which form maximum boiling azeotrope (C) Having very wide boiling points (D) Which form minimum boiling azeotrope

Last Answer : (C) Having very wide boiling points

Flash point of a liquid petroleum fuel gives an idea about its (A) Volatility (B) Explosion hazards characteristics (C) Nature of boiling point diagram (D) All (A), (B) and (C)

Description : Flash point of a liquid petroleum fuel gives an idea about its (A) Volatility (B) Explosion hazards characteristics (C) Nature of boiling point diagram (D) All (A), (B) and (C)

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

At boiling point of liquids, its : (1) Temperature increases (2) Atmospheric pressure increases (3) Timperature remains increases (4) Vapour pressure decreases

Description : At boiling point of liquids, its : (1) Temperature increases (2) Atmospheric pressure increases (3) Timperature remains increases (4) Vapour pressure decreases

Last Answer : (3) Timperature remains increases

At boiling point of liquids, its – (1) Temperature increases (2) Atmospheric pressure increases (3) Temperature remains constant (4) Vapour pressure decreases

Description : At boiling point of liquids, its – (1) Temperature increases (2) Atmospheric pressure increases (3) Temperature remains constant (4) Vapour pressure decreases

Last Answer : (3) Temperature remains constant Explanation: An interesting property of matter is that its temperature remains constant during a phase change, assuming its surrounding pressure is constant. A liquid changes into gaseous state at a constant temperature called its boiling point.

Which of the following decreases with increase in pressure? (A) Melting point of ice (B) Melting point of wax (C) Boiling point of liquids (D) None of these

Description : Which of the following decreases with increase in pressure? (A) Melting point of ice (B) Melting point of wax (C) Boiling point of liquids (D) None of these

Last Answer : (A) Melting point of ice

At boiling point of liquids, its (1) Temperature increases (2) Atmospheric pressure increases (3) Temperature remains constant (4) Vapour pressure decreases

Description : At boiling point of liquids, its (1) Temperature increases (2) Atmospheric pressure increases (3) Temperature remains constant (4) Vapour pressure decreases 

Last Answer : Temperature remains constant

Plasticisers are high boiling liquids added to plastic polymers to impart toughness and flexibility at ordinary temperature. Which of the following is not a plasticiser? (A) Ethylene glycol (B) Stearic acid estors (C) Tricresyl phosphate (D) Esters of phthalic acid

Description : Plasticisers are high boiling liquids added to plastic polymers to impart toughness and flexibility at ordinary temperature. Which of the following is not a plasticiser? (A) Ethylene glycol (B) Stearic acid estors (C) Tricresyl phosphate (D) Esters of phthalic acid

Last Answer : (A) Ethylene glycol

What difference in properties between two liquids allows distillation to be done?

Description : What difference in properties between two liquids allows distillation to be done?

Last Answer : Need answer

Distillation can be used to separate solutions of miscible liquids because ?

Description : Distillation can be used to separate solutions of miscible liquids because ?

Last Answer : Distillation works because liquids boil at different temperatures. Roughly speaking, in order to separate two liquids, you should heat the mixture to a temperature where one of the liquids (but not the ... boil off, leaving the second liquid behind; you can collect the first liquid in a condenser.

Give any two applications of simple distillation.Describe method of separation of two immiscible liquids.

Description : Give any two applications of simple distillation.Describe method of separation of two immiscible liquids.

Last Answer : Applications of simple distillation(0.5 2) 1) Preparation of distilled water and water for injection. 2)Recovery of alcohol in preparation of dry extracts 3)Many volatile oils and ... proportion The distillate can be collected in Florentine receiver for separation of oil & water.

Pick out the wrong statement: (A) The capacity of an evaporator is reduced by the boiling point elevation (B) Corrosive liquid is normally passed through the tubes in a shell and tube heat exchanger (C) Steam jet ejector is used for vapor compression in a thermal recompression evaporator (D) Heat sensitive materials should be concentrated in high pressure evaporators

Description : Pick out the wrong statement: (A) The capacity of an evaporator is reduced by the boiling point elevation (B) Corrosive liquid is normally passed through the tubes in a ... recompression evaporator (D) Heat sensitive materials should be concentrated in high pressure evaporators

Last Answer : (D) Heat sensitive materials should be concentrated in high pressure evaporators

Bottom product of atmospheric pressure crude oil distillation column is termed as (A) Reduced crude (B) Heavy ends (C) Asphalt (D) Residuum

Description : Bottom product of atmospheric pressure crude oil distillation column is termed as (A) Reduced crude (B) Heavy ends (C) Asphalt (D) Residuum

Last Answer : (A) Reduced crude

The amount of steam required per unit quantity of distillate in case of steam distillation will be reduced by (A) Raising the temperature (B) Lowering the total pressure (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : The amount of steam required per unit quantity of distillate in case of steam distillation will be reduced by (A) Raising the temperature (B) Lowering the total pressure (C) Both (A) and (B) (D) Neither (A) nor (B)

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

A liquid with high boiling point decomposes on simple distillation but it can be steam distilled for its purification .Explain how is it possible?

Description : A liquid with high boiling point decomposes on simple distillation but it can be steam distilled for its purification .Explain how is it possible?

Last Answer : In steam distillation boiling occurs when vapour pressure of organic compound & steam becomes equal to atmospheric pressure. As vapour pressure of water is higher than the organic liquid. ... organic liquid vaporizes at a temperature below its boiling point in steam distillation without decomposing.

Steam distillation is used for separation of high boiling (A) Substances from non-volatile impurities (B) Volatile impurity from still higher boiling substances (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Steam distillation is used for separation of high boiling (A) Substances from non-volatile impurities (B) Volatile impurity from still higher boiling substances (C) Both (A) and (B) (D) Neither (A) nor (B)

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

When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is __________ distillation. (A) Continuous (B) Steam (C) Azeotropic (D) None of these

Description : When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is __________ distillation. (A) Continuous (B) Steam (C) Azeotropic (D) None of these

Last Answer : (B) Steam

Which of the following statements is not true about triacylglycerols? (a) When solids and semisolids at room temperature, they are called fats. (b) When liquids at room temperature, they are called oils. (c) When hydrolyzed, they produce glycerol and carboxylate salts. (d) Triacylglycerols with low melting points are composed of saturated fatty acids, causing them to be liquids at room temperature

Description : Which of the following statements is not true about triacylglycerols? (a) When solids and semisolids at room temperature, they are called fats. (b) When liquids at room temperature, they are ... low melting points are composed of saturated fatty acids, causing them to be liquids at room temperature

Last Answer : Triacylglycerols with low melting points are composed of saturated fatty acids, causing them to be liquids at room temperature

The probability of knocking in diesel engines is increased by a. High self-ignition temperature. b. Low volatility. c. High viscosity. d. all of the above

Description : The probability of knocking in diesel engines is increased by a. High self-ignition temperature. b. Low volatility. c. High viscosity. d. all of the above

Last Answer : ANSWER d. all of the above

The probability of knocking in diesel engines is increased by a. High self-ignition temperature. b. Low volatility. c. High viscosity. d. All of the above

Description : The probability of knocking in diesel engines is increased by a. High self-ignition temperature. b. Low volatility. c. High viscosity. d. All of the above

Last Answer : ANSWER d. all of the above

For a binary mixture with low relative volatility, continuous rectification to get pure products will require (A) Low reflux ratio (B) Less number of trays (C) Small cross-section column (D) High reflux ratio

Description : For a binary mixture with low relative volatility, continuous rectification to get pure products will require (A) Low reflux ratio (B) Less number of trays (C) Small cross-section column (D) High reflux ratio

Last Answer : (D) High reflux ratio

Pick out the wrong statement. Generally for physical adsorption, a gas of (A) Higher molecular weight is adsorbed in preference to a gas of low molecular weight (B) High critical temperature is adsorbed in preference to a gas of low critical temperature (C) Low volatility is adsorbed in preference to a gas of high volatility (D) None of these

Description : Pick out the wrong statement. Generally for physical adsorption, a gas of (A) Higher molecular weight is adsorbed in preference to a gas of low molecular weight (B) High critical temperature ... volatility is adsorbed in preference to a gas of high volatility (D) None of these

Last Answer : (D) None of these

The melting and boiling points of ionic solids are (a) High (b) Low (c) Very low (d) Of intermediate range

Description : The melting and boiling points of ionic solids are (a) High (b) Low (c) Very low (d) Of intermediate range

Last Answer : Ans:(a)

Leidenfrost point is a term concerned with the (A) Condensation of the saturated vapor on a cold surface (B) Concentration of a corrosive solution by evaporation (C) Heat transfer between two highly viscous liquids (D) Boiling of a liquid on a hot surface

Description : Leidenfrost point is a term concerned with the (A) Condensation of the saturated vapor on a cold surface (B) Concentration of a corrosive solution by evaporation (C) Heat transfer between two highly viscous liquids (D) Boiling of a liquid on a hot surface

Last Answer : (D) Boiling of a liquid on a hot surface

Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to __________ boiling. (A) Film (B) Nucleate (C) Transition (D) All modes of

Description : Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to __________ boiling. (A) Film (B) Nucleate (C) Transition (D) All modes of

Last Answer : Option A