The activity and selectivity of zeolites as catalyst is based on :-

The activity and selectivity of zeolites as catalyst is based on :-
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The activity and selectivity of zeolites as catalyst is based on :- A. Their pore size B. Size of their cavities on the surface C. Both D. None
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Catalyst carriers (A) Have very high selectivity (B) Increase the activity of a catalyst (C) Provide large surface area with a small amount of active material (D) Inhibit catalyst poisoning

Description : Catalyst carriers (A) Have very high selectivity (B) Increase the activity of a catalyst (C) Provide large surface area with a small amount of active material (D) Inhibit catalyst poisoning

Last Answer : (C) Provide large surface area with a small amount of active material

Carbon particles accumulated on the catalyst used in the gas oil cracking lies in the category of __________ poison. (A) Deposited (B) Chemisorbed (C) Selectivity (D) Stability

Description : Carbon particles accumulated on the catalyst used in the gas oil cracking lies in the category of __________ poison. (A) Deposited (B) Chemisorbed (C) Selectivity (D) Stability

Last Answer : (A) Deposited

In autocatalytic reactions, (A) One of the reactants acts as a catalyst (B) One of the products acts as a catalyst (C) Catalysts have very high selectivity (D) No catalyst is used

Description : In autocatalytic reactions, (A) One of the reactants acts as a catalyst (B) One of the products acts as a catalyst (C) Catalysts have very high selectivity (D) No catalyst is used

Last Answer : (B) One of the products acts as a catalyst

A catalyst inhibitor (A) Lessens its selectivity (B) May be useful for suppressing undesirable side reactions (C) Is added in small quantity during the catalyst manufacture itself (D) All (A), (B) and (C

Description : A catalyst inhibitor (A) Lessens its selectivity (B) May be useful for suppressing undesirable side reactions (C) Is added in small quantity during the catalyst manufacture itself (D) All (A), (B) and (C

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

The ß-adrenergic blocker which possesses both ß1 selectivity as well as intrinsic sympathomimetic activity is (a) Alprenolol (b) Atenolol (c) Acebutolol (d) Metoprolol

Description : The ß-adrenergic blocker which possesses both ß1 selectivity as well as intrinsic sympathomimetic activity is (a) Alprenolol (b) Atenolol (c) Acebutolol (d) Metoprolol

Last Answer : Ans: C

What do you mean by activity and selectivity of catalysis?

Description : What do you mean by activity and selectivity of catalysis? 

Last Answer : Ans. Activity of catalyst means to increase the extent of chemisorption. Selectivity of Catalyst means to direct a reaction to form selective product.

The β adrenergic blocker having β1 selectivity, intrinsic sympathomimetic activity and membrane stabilizing property is: A. Carvedilol B. Atenolol C. Acebutolol D. Metoprolol

Description : The β adrenergic blocker having β1 selectivity, intrinsic sympathomimetic activity and membrane stabilizing property is: A. Carvedilol B. Atenolol C. Acebutolol D. Metoprolol

Last Answer : C. Acebutolol

The β adrenergic blocker having β 1 selectivity, intrinsic sympathomimetic activity and membrane stabilizing property is: A. Carvedilol B. Atenolol C. Acebutolol D. Metoprolol

Description : The β adrenergic blocker having β 1 selectivity, intrinsic sympathomimetic activity and membrane stabilizing property is: A. Carvedilol B. Atenolol C. Acebutolol D. Metoprolol

Last Answer : C. Acebutolol

Which of the following statements about the zeolites is false?

Description : Which of the following statements about the zeolites is false?

Last Answer : Which of the following statements about the zeolites is false? A. Some of the ` ... D. Zeolites are aluminosilicates having three dimensional network

Zeolites are :-

Description : Zeolites are :-

Last Answer : Zeolites are :- A. Water softner B. Catalyst C. cation exchanger D. All of these

Permanent hardness of water, due to sulphates of the metal, can be destroyed by the use of (1) Nitrates (2) Zeolites (3) Sulphonates (4) None of these

Description : Permanent hardness of water, due to sulphates of the metal, can be destroyed by the use of (1) Nitrates (2) Zeolites (3) Sulphonates (4) None of these

Last Answer : (2) Zeolites Explanation: Zeolites are crystalline solids structures made of silicon, aluminum and oxygen that form a framework with cavities and channels inside where cations, water and/or small molecules may reside.

What are the Uses of Zeolites?

Description : What are the Uses of Zeolites?

Last Answer : Ans. They are used as shape selective catalysts To remove the hardness of water

What are zeolites?

Description : What are zeolites?

Last Answer : Ans. They are the alumino silicates and used as shape selective catalysts. Eg.ZSM-5

Which property of Zeolites make it suitable to soften hard water?

Description : Which property of Zeolites make it suitable to soften hard water?

Last Answer : Ans-Sodium ions are exchanged by calcium and magnesium ions

Molecular sieves are porous (A) Alumina (B) Silica (C) Synthetic zeolites crystals/metal alumino-silicates (D) None of these

Description : Molecular sieves are porous (A) Alumina (B) Silica (C) Synthetic zeolites crystals/metal alumino-silicates (D) None of these

Last Answer : (C) Synthetic zeolites crystals/metal alumino-silicates

Zeolite removes both temporary as well as permanent hardness of water by precipitating calcium and magnesium present in water as insoluble zeolites. Used zeolite is regenerated by flushing with the solution of (A) Calcium sulphate (B) Sodium chloride(C) Sodium sulphate(D) Magnesium chloride

Description : Zeolite removes both temporary as well as permanent hardness of water by precipitating calcium and magnesium present in water as insoluble zeolites. Used zeolite is regenerated by flushing with the solution of (A) Calcium sulphate (B) Sodium chloride (C) Sodium sulphate (D) Magnesium chloride

Last Answer : (B) Sodium chloride

Permanent hardness of water can be removed by (A) Addition of soda ash to it (B) Treating it with zeolites (C) Passing it through sodium hexametaphosphate (D) All (A), (B), and (C)

Description : Permanent hardness of water can be removed by (A) Addition of soda ash to it (B) Treating it with zeolites (C) Passing it through sodium hexametaphosphate (D) All (A), (B), and (C)

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

Finely divided catalyst has greater surface area and has greater catalytic activity than the compact solid. If a total surface area of 6291456 `cm^(2)

Description : Finely divided catalyst has greater surface area and has greater catalytic activity than the compact solid. If a total surface area of 6291456 `cm^(2)

Last Answer : Finely divided catalyst has greater surface area and has greater catalytic activity than the compact solid. If a total ... B. `80` C. `20` D. `22`

The temperature at which the catalytic activity of the catalyst is maximum, is called (1) room temperature (2) critical temperature (3) absolute temperature (4) optimum temperature

Description : The temperature at which the catalytic activity of the catalyst is maximum, is called (1) room temperature (2) critical temperature (3) absolute temperature (4) optimum temperature

Last Answer : d) optimum temperature

Iron is not used alone as a catalyst in ammonia synthesis, because (A) Its activity declines rapidly, if heated to above 520°C (B) It decomposes ammonia (C) It gets oxidised above 500°C (D) None of these

Description : Iron is not used alone as a catalyst in ammonia synthesis, because (A) Its activity declines rapidly, if heated to above 520°C (B) It decomposes ammonia (C) It gets oxidised above 500°C (D) None of these

Last Answer : (A) Its activity declines rapidly, if heated to above 520°C

A catalyst loses its activity due to (A) Loss in surface area of the active component (B) Agglomeration of metal particles caused by thermal sintering of the solid surface (C) Covering of the catalytic active sites by a foreign substance (D) All (A), (B) and (C)

Description : A catalyst loses its activity due to (A) Loss in surface area of the active component (B) Agglomeration of metal particles caused by thermal sintering of the solid surface (C) Covering of the catalytic active sites by a foreign substance (D) All (A), (B) and (C)

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

In Langmuir treatment of adsorption, (A) Whole surface of the catalyst does not have the same activity for adsorption and there is attraction between the adsorbed molecule (B) Whole surface of the catalyst is essentially uniform and the adsorbed molecule has no effect on the rate of adsorption per site (C) All the adsorption does not take place by the same mechanism (D) Extent of adsorption is more than one complete monomolecular layer on the surface

Description : In Langmuir treatment of adsorption, (A) Whole surface of the catalyst does not have the same activity for adsorption and there is attraction between the adsorbed molecule (B) Whole surface of ... same mechanism (D) Extent of adsorption is more than one complete monomolecular layer on the surface

Last Answer : (B) Whole surface of the catalyst is essentially uniform and the adsorbed molecule has no effect on the rate of adsorption per site

A catalyst promoter (A) Improves the activity of a catalyst (B) Acts as a catalyst support (C) Itself has very high activity (D) All (A), (B) and (C)

Description : A catalyst promoter (A) Improves the activity of a catalyst (B) Acts as a catalyst support (C) Itself has very high activity (D) All (A), (B) and (C)

Last Answer : (A) Improves the activity of a catalyst

Low pressure Zeigler process of polythene manufacture (A) Employs a pressure of 30 kgf/cm2 (B) Achieves an yield of 95-98% based on ethylene (C) Produces very low density polythene (D) Does not use any catalyst for polymerisation

Description : Low pressure Zeigler process of polythene manufacture (A) Employs a pressure of 30 kgf/cm2 (B) Achieves an yield of 95-98% based on ethylene (C) Produces very low density polythene (D) Does not use any catalyst for polymerisation

Last Answer : (B) Achieves an yield of 95-98% based on ethylene

What is the meaning of selectivity permeable?

Description : What is the meaning of selectivity permeable?

Last Answer : Selective permeability refers to the function of plasmamembranes that is needed to maintain homeostasis in a cell andprevent foriegn substances from entering through the cellswalls.Some molecules can pass, some are blocked

What is the process in which water moves from an area of high concentration to an area of low concentration across a selectivity permeable membrane?

Description : What is the process in which water moves from an area of high concentration to an area of low concentration across a selectivity permeable membrane?

Last Answer : Need answer

Diquat, Paraquat, Oxadiargyl and Glyphosate etc. belongs to the selectivity group

Description : Diquat, Paraquat, Oxadiargyl and Glyphosate etc. belongs to the selectivity group

Last Answer : Ans.Non-selective herbicides

2, 4-D, Simazine, Atrazine and Fluchloralin belongs to the selectivity group

Description : 2, 4-D, Simazine, Atrazine and Fluchloralin belongs to the selectivity group

Last Answer : Ans.Selective herbicides

There are two properties of the cell necessary to maintain nonequilibrium cellular composition; the first is selectivity and the second is energy conversion. Which of the following statement(s) is/are true concerning energy converting transport? a. The site of energy conversion and transport in the plasma membrane involves the phospholipid component b. The Na+-K++-ATPase derives energy from hydrolysis of extracellular ATP c. In some systems, energy inherent in the transmembrane ion gradient can be used to drive transport of a second species d. Examples of species transported via secondary active transport include hydrogen ions, calcium, amino acids and glucose

Description : There are two properties of the cell necessary to maintain nonequilibrium cellular composition; the first is selectivity and the second is energy conversion. Which of the following statement(s ... transported via secondary active transport include hydrogen ions, calcium, amino acids and glucose

Last Answer : Answer: c, d The selectivity of the plasma membrane, although impressive, cannot account for the nonequilibrium composition of living cells. A cell can be maintained in a nonequilibrium state only by ... to drive the transport of a second species such as protons, calcium, amino acids, or glucose

A striking feature of living cells is a marked difference between the composition of the cytosol and the extracellular milieu. Which of the following statement(s) concerning the mechanisms of maintenance of these differences is/are true? a. The cell membrane is able to maintain a 10,000 fold gradient between the extracellular concentration of ionized calcium and the intracellular concentration b. The key to these differences is the fact that the plasma membrane is normally impermeable to sodium, potassium and calcium c. The selectivity of biologic membranes is highly consistent and seldom changes d. The selectivity of cell membranes relates only to ions and not organic compounds

Description : A striking feature of living cells is a marked difference between the composition of the cytosol and the extracellular milieu. Which of the following statement(s) concerning the mechanisms of maintenance ... d. The selectivity of cell membranes relates only to ions and not organic compounds

Last Answer : Answer: a The survival of the cell requires that cytosolic composition be maintained within narrow limits, despite the constant influx of nutrients and the simultaneous outflow of waste. A ... be altered drastically as a result of regulatory or signaling processes that occur within the cell

Stacking antenna elements A. increases sensitivity to weak signals B. will suppress odd harmonics C. decrease signal to noise ratio D. increases selectivity

Description : Stacking antenna elements A. increases sensitivity to weak signals B. will suppress odd harmonics C. decrease signal to noise ratio D. increases selectivity

Last Answer : A. increases sensitivity to weak signals

What causes image interference? A. Low gain B. High IF C. Poor front-end selectivity D. Low signal-to-noise ratio

Description : What causes image interference? A. Low gain B. High IF C. Poor front-end selectivity D. Low signal-to-noise ratio

Last Answer : C. Poor front-end selectivity

What is the selectivity index, if the grade of tailings & concentrate is the same? (A) 0 (B) ∞ (C) 1 (D) 0.5

Description : What is the selectivity index, if the grade of tailings & concentrate is the same? (A) 0 (B) ∞ (C) 1 (D) 0.5

Last Answer : (C) 1

_________ is defined as the geometric mean of the relative rejections and the relative recoveries of two minerals. (A) Separation efficiency (B) Selectivity index (C) Concentration ratio (D) None of these

Description : _________ is defined as the geometric mean of the relative rejections and the relative recoveries of two minerals. (A) Separation efficiency (B) Selectivity index (C) Concentration ratio (D) None of these

Last Answer : (B) Selectivity index

The reciprocal of stripping factor is termed as (A) Selectivity index (B) Relative volatility (C) Absorption factor (D) Murphree efficiency

Description : The reciprocal of stripping factor is termed as (A) Selectivity index (B) Relative volatility (C) Absorption factor (D) Murphree efficiency

Last Answer : (C) Absorption factor

Pick out the correct statement. (A) In case of liquid-liquid extraction, no separation is possible, if the selectivity of the solvent used is unity (B) With increase in temperature, the selectivity of the solvent used in solvent extraction decreases (C) The selectivity of solvent used in solvent extraction is unity at the plait point (D) All (A), (B) and (C)

Description : Pick out the correct statement. (A) In case of liquid-liquid extraction, no separation is possible, if the selectivity of the solvent used is unity (B) With increase in temperature, the selectivity of the solvent used ... in solvent extraction is unity at the plait point (D) All (A), (B) and (C)

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

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

Description : 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 ... unity (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum

Last Answer : (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum

Selectivity of the solvent used in solvent extraction should be (A) 1 (B) > 1 (C) < 1 (D) 0

Description : Selectivity of the solvent used in solvent extraction should be (A) 1 (B) > 1 (C) < 1 (D) 0

Last Answer : (B) > 1

The solvent used in liquid-liquid extraction should have __________ less than one. (A) Selectivity (B) Distribution co-efficient(C) Both (A) and (B)(D) Neither (A) nor (B)

Description : The solvent used in liquid-liquid extraction should have __________ less than one. (A) Selectivity (B) Distribution co-efficient (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (D) Neither (A) nor (B)

In which of the following unit operations, the selectivity is an important parameter? (A) Distillation (B) Solvent extraction (C) Absorption (D) None of these

Description : In which of the following unit operations, the selectivity is an important parameter? (A) Distillation (B) Solvent extraction (C) Absorption (D) None of these

Last Answer : (B) Solvent extraction

The expression, y(1 - x)/x(1 - y) is for (A) Absorption factor (B) Relative volatility (C) Selectivity (D) Murphree efficiency

Description : The expression, y(1 - x)/x(1 - y) is for (A) Absorption factor (B) Relative volatility (C) Selectivity (D) Murphree efficiency

Last Answer : (B) Relative volatility

In liquid extraction, if the selectivity is unity, then (A) Separation of the constituents is the most effective (B) No separation will occur (C) Amount of solvent required will be minimum (D) Solvent flow rate should be very low

Description : In liquid extraction, if the selectivity is unity, then (A) Separation of the constituents is the most effective (B) No separation will occur (C) Amount of solvent required will be minimum (D) Solvent flow rate should be very low

Last Answer : (B) No separation will occur

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

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? (A) Cost (B) Availability(C) Toxicity(D) Selectivity

Description : 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 ... ? (A) Cost (B) Availability (C) Toxicity (D) Selectivity

Last Answer : (D) Selectivity

Which of the following criteria does not pertain to facilitated transport? (a) Transport saturation (b) Uphill transport (c) Requirement of special membrane proteins (d) High selectivity

Description : Which of the following criteria does not pertain to facilitated transport? (a) Transport saturation (b) Uphill transport (c) Requirement of special membrane proteins (d) High selectivity

Last Answer : (b) Uphill transport

In Orsat's apparatus, ammoniacal cuprous chloride is used for selectivity absorbing (A) CO (B) CO2 (C) O2 (D) H2O

Description : In Orsat's apparatus, ammoniacal cuprous chloride is used for selectivity absorbing (A) CO (B) CO2 (C) O2 (D) H2O

Last Answer : (A) CO

______________________ has the advantage of being high in selectivity, low cost, immediacy, and interactive capabilities. 1. Direct mail 2. Outdoor 3. Online 4. Radio 5. None of these

Description : ______________________ has the advantage of being high in selectivity, low cost, immediacy, and interactive capabilities. 1. Direct mail 2. Outdoor 3. Online 4. Radio 5. None of these

Last Answer : Online

The ratio of moles of a reactant converted into the desired product to that converted into unwanted product is called (A) Operational yield (B) Relative yield (C) Selectivity (D) None of these

Description : The ratio of moles of a reactant converted into the desired product to that converted into unwanted product is called (A) Operational yield (B) Relative yield (C) Selectivity (D) None of these

Last Answer : (C) Selectivity

Pick out the wrong statement. (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity(B) For an ideal mixed reactor at steady state, the exit stream has the samecomposition as fluid within the reactor and the space time is equivalent toholding time for constant density system(C) Plug flow reactor (PFR) is always smaller than mixed reactor for allpositive reaction orders for a particular duty(D) Reaction rate does not decrease appreciably as the reaction proceeds incase of an autocatalytic reaction

Description : Pick out the wrong statement. (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity(B) For an ideal ... D) Reaction rate does not decrease appreciably as the reaction proceeds in case of an autocatalytic reaction

Last Answer : (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity

A stirred tank reactor compared to tubular-flow reactor provides (A) More uniform operating conditions (B) Permits operation at the optimum temperature for a long reaction time (C) Higher overall selectivity for a first order consecutive reaction (D) All (A), (B) and (C

Description : A stirred tank reactor compared to tubular-flow reactor provides (A) More uniform operating conditions (B) Permits operation at the optimum temperature for a long reaction time (C) Higher overall selectivity for a first order consecutive reaction (D) All (A), (B) and (C

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