. B.E.T. method can be used to determine the __________ of a porous catalyst. (A) Solid density (B) Pore volume (C) Surface area (D) All (A), (B) and (C)

. B.E.T. method can be used to determine the __________ of a porous
catalyst.
(A) Solid density
(B) Pore volume
(C) Surface area
(D) All (A), (B) and (C)
by

1 Answer

Answer :

(C) Surface area
by

Related questions

Brunauer, Emmet and Teller (BET) equation is used to determine the specific surface area of a porous particle but not the pore volume & the porosity of the catalyst bed. Which of the following postulates is not used to derive BET equation? (A) Langmuir's assumption applies to every adsorbed layer (B) There is no dynamic equilibrium between successive layer (C) The adsorbed layer may be polymolecular in thickness and the heat of adsorption in each layer (except the first one) is involved in each of the evaporation process (D) None of these

Description : Brunauer, Emmet and Teller (BET) equation is used to determine the specific surface area of a porous particle but not the pore volume & the porosity of the catalyst bed. Which of the following postulates ... (except the first one) is involved in each of the evaporation process (D) None of these

Last Answer : (B) There is no dynamic equilibrium between successive layer

Helium-mercury method can be used to determine the __________ of the catalyst particle. (A) Pore volume (B) Solid density (C) Porosity (D) All (A), (B), & (C)

Description : Helium-mercury method can be used to determine the __________ of the catalyst particle. (A) Pore volume (B) Solid density (C) Porosity (D) All (A), (B), & (C)

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

BET apparatus is used to determine the (A) Specific surface of a porous catalyst (B) Pore size distribution (C) Pore diameter (D) Porosity of the catalyst bed

Description : BET apparatus is used to determine the (A) Specific surface of a porous catalyst (B) Pore size distribution (C) Pore diameter (D) Porosity of the catalyst bed

Last Answer : (A) Specific surface of a porous catalyst

Helium-mercury method is used for the measurement of the __________ of the catalyst. (A) Surface area (B) Porosity (C) Pore volume (D) Both (B) & (C)

Description : Helium-mercury method is used for the measurement of the __________ of the catalyst. (A) Surface area (B) Porosity (C) Pore volume (D) Both (B) & (C)

Last Answer : (D) Both (B) & (C)

Which of the following factors control the deactivation of a porous catalyst pellet? (A) Decay reactions (B) Pore diffusion (C) Form of surface attack by poison (D) All (A), (B) and (C)

Description : Which of the following factors control the deactivation of a porous catalyst pellet? (A) Decay reactions (B) Pore diffusion (C) Form of surface attack by poison (D) All (A), (B) and (C)

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

If pore diffusion is the controlling step in a solid catalysed reaction, the catalyst (A) Porosity is very important (B) Porosity is of less importance (C) Internal surface area is utilised efficiently (D) None of these

Description : If pore diffusion is the controlling step in a solid catalysed reaction, the catalyst (A) Porosity is very important (B) Porosity is of less importance (C) Internal surface area is utilised efficiently (D) None of these

Last Answer : (B) Porosity is of less importance

Pick out the wrong statement. (A) Exit age description function (E) and internal age distribution function (I) are related as, E = -(dI/dθ) (B) Chemisorption studies are useful in the determination of catalyst surface area and pore size distribution (C) A higher temperature favours the reaction of higher activation energy (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

Description : Pick out the wrong statement. (A) Exit age description function (E) and internal age distribution function (I) are related as, E = -(dI/dθ) (B) Chemisorption studies are useful in the ... energy (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

Last Answer : (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

B.E.T. method of finding out surface area of a catalyst, uses the extension of __________ isotherm. (A) Langmuir (B) Freundlich (C) Tempkin (D) None of these

Description : B.E.T. method of finding out surface area of a catalyst, uses the extension of __________ isotherm. (A) Langmuir (B) Freundlich (C) Tempkin (D) None of these

Last Answer : (A) Langmuir

__________ gas is normally employed in B.E.T. method of finding out the surface area of catalyst. (A) N2 (B) H2(C) CO2(D) He

Description : __________ gas is normally employed in B.E.T. method of finding out the surface area of catalyst. (A) N2 (B) H2 (C) CO2 (D) He

Last Answer : (A) N2

In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for (A) Fast reactions in catalyst of small pore diameter (B) Fast reaction in catalyst of large pore diameter (C) Slow reactions in catalyst of small pore diameter (D) Slow reactions in catalyst of large pore diameter

Description : In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for (A) Fast reactions in catalyst of small pore diameter (B) Fast reaction in catalyst ... reactions in catalyst of small pore diameter (D) Slow reactions in catalyst of large pore diameter

Last Answer : (C) Slow reactions in catalyst of small pore diameter

Effectiveness factor (E) of a catalyst pellet is defined as, E = (actual rate within pore of the catalyst)/(rate if not snowed by pore diffusion), Effectiveness factor for a first order reaction is given by (where, T = Thiele modulus) (A) tan hT/T (B) tan T/T(C) tan hT/tan T(D) None of these

Description : Effectiveness factor (E) of a catalyst pellet is defined as, E = (actual rate within pore of the catalyst)/(rate if not snowed by pore diffusion), Effectiveness factor for a first order reaction is given by (where, T = Thiele modulus) (A) tan hT/T (B) tan T/T (C) tan hT/tan T (D) None of these

Last Answer : (A) tan hT/T

Pick out the correct statement. (A) A lower temperature favours the reaction of lower activation energy (B) The dispersion number for a reactor/vessel is uL/D (C) The rate controlling step in a reaction involving many steps is the fastest step (D) Pore volume and porosity of a catalyst is measured by Brunauer￾Emmett-Teller (BET) technique

Description : Pick out the correct statement. (A) A lower temperature favours the reaction of lower activation energy (B) The dispersion number for a reactor/vessel is uL/D (C) The rate controlling step in ... step (D) Pore volume and porosity of a catalyst is measured by Brunauer￾Emmett-Teller (BET) technique

Last Answer : (A) A lower temperature favours the reaction of lower activation energy

A first order reaction A → B occurs in an isothermal porous catalyst pellet of spherical shape. If the concentration of A at the centre of the pellet is much less than at the external surface, the process is limited by (A) Diffusion within the pellet (B) Reaction (C) External mass transfer (D) None of the above

Description : A first order reaction A → B occurs in an isothermal porous catalyst pellet of spherical shape. If the concentration of A at the centre of the pellet is much less than at the external surface, the ... A) Diffusion within the pellet (B) Reaction (C) External mass transfer (D) None of the above

Last Answer : (A) Diffusion within the pellet

The importance of diffusion in a catalyst are increased by (A) Large catalyst particle size (B) An active surface of the catalyst (C) Small pore diameter (D) All (A), (B) and (C)

Description : The importance of diffusion in a catalyst are increased by (A) Large catalyst particle size (B) An active surface of the catalyst (C) Small pore diameter (D) All (A), (B) and (C)

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

If Thiele modulus is __________, then the pore diffusion resistance in a catalyst may be considered as negligible. (A) 0 (B) ∞ (C) < 0.5 (D) > 0.5

Description : If Thiele modulus is __________, then the pore diffusion resistance in a catalyst may be considered as negligible. (A) 0 (B) ∞ (C) < 0.5 (D) > 0.5

Last Answer : (C) < 0.5

Effectiveness factor of a catalyst pellet is a measure of the __________ resistance. (A) Pore diffusion (B) Gas film (C) Chemical reaction (D) None of these

Description : Effectiveness factor of a catalyst pellet is a measure of the __________ resistance. (A) Pore diffusion (B) Gas film (C) Chemical reaction (D) None of these

Last Answer : (A) Pore diffusion

Bulk diffusion in catalyst pore __________ with increase in pressure. (A) Increases (B) Decreases (C) Remains unchanged (D) Increases exponentially

Description : Bulk diffusion in catalyst pore __________ with increase in pressure. (A) Increases (B) Decreases (C) Remains unchanged (D) Increases exponentially

Last Answer : (B) Decreases

Which of the following resistances is not involved in a gas phase catalytic (gas-solid) reaction?(A) Ash resistance (B) Gas film and pore surface diffusion resistances for reactants (C) Surface phenomenon resistance (D) Gas film and pore surface diffusion resistances for products

Description : Which of the following resistances is not involved in a gas phase catalytic (gas-solid) reaction? (A) Ash resistance (B) Gas film and pore surface diffusion resistances for reactants (C) Surface phenomenon resistance (D) Gas film and pore surface diffusion resistances for products

Last Answer : (A) Ash resistance

For a first order chemical reaction in a porous catalyst, the Thiele modulus is 10. The effectiveness factor is approximately equal to (A) 0 (B) 1 (C) 0.1 (D) 0.5

Description : For a first order chemical reaction in a porous catalyst, the Thiele modulus is 10. The effectiveness factor is approximately equal to (A) 0 (B) 1 (C) 0.1 (D) 0.5

Last Answer : (C) 0.1

For a first order isothermal chemical reaction in a porous catalyst, the effectiveness factor is 0.3. The effectiveness factor will increase if the (A) Catalyst size is reduced or the catalyst diffusivity is reduced (B) Catalyst size is reduced or the catalyst diffusivity is increased (C) Catalyst size is increased or the catalyst diffusivity is reduced(D) Catalyst size is increased or the catalyst diffusivity is increased

Description : For a first order isothermal chemical reaction in a porous catalyst, the effectiveness factor is 0.3. The effectiveness factor will increase if the (A) Catalyst size is reduced or the ... the catalyst diffusivity is reduced (D) Catalyst size is increased or the catalyst diffusivity is increased

Last Answer : (B) Catalyst size is reduced or the catalyst diffusivity is increased

Catalyst used in the manufacture of sulphuric acid by chamber & contact processes are respectively (A) V2O5 & Cr2O3 . (B) Oxides of nitrogen & Cr2O3 (C) V2O5 on a porous carrier & oxides of nitrogen (D) Oxides of nitrogen & V2O5 on a porous carrier

Description : Catalyst used in the manufacture of sulphuric acid by chamber & contact processes are respectively (A) V2O5 & Cr2O3 . (B) Oxides of nitrogen & Cr2O3 (C) V2O5 on a porous carrier & oxides of nitrogen (D) Oxides of nitrogen & V2O5 on a porous carrier

Last Answer : (D) Oxides of nitrogen & V2O5 on a porous carrier

Temperature during hydrogenation of oil should not be more than 200°C, otherwise it will result in (A) Pyrolysis of oil(B) Sintering of porous catalyst(C) Hydrogen embrittlement(D) All (A), (B) and (C)

Description : Temperature during hydrogenation of oil should not be more than 200°C, otherwise it will result in (A) Pyrolysis of oil (B) Sintering of porous catalyst (C) Hydrogen embrittlement (D) All (A), (B) and (C)

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

Overall rate of reaction in a heterogeneous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually __________ the concentration of catalyst, if it doesnot entail a chain mechanism.(A) Proportional to(B) Independent of(C) Inversely proportional to(D) Proportional to the square o

Description : Overall rate of reaction in a heterogeneous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually __________ the concentration of ... to (B) Independent of (C) Inversely proportional to (D) Proportional to the square o

Last Answer : (A) Proportional to

The Knudsen diffusivity is dependent on the (A) Molecular velocity only (B) Pore radius of the catalyst only (C) Molecular mean free path only (D) Molecular velocity and pore radius of the catalyst

Description : The Knudsen diffusivity is dependent on the (A) Molecular velocity only (B) Pore radius of the catalyst only (C) Molecular mean free path only (D) Molecular velocity and pore radius of the catalyst

Last Answer : (D) Molecular velocity and pore radius of the catalyst

If the catalyst pore size is small in comparison with the mean free path, collisions with the pore wall controls the process'. The diffusivity under this condition is called 'Knudsen diffusivity', which is affected by the (A) Pressure (B) Temperature (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : If the catalyst pore size is small in comparison with the mean free path, collisions with the pore wall controls the process'. The diffusivity under this condition is called 'Knudsen diffusivity', which is affected by the (A) Pressure (B) Temperature (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (B) Temperature

If a solid-gas non-catalytic reaction occurs at very high temperature, the rate controlling step is the __________ diffusion. (A) Film (B) Ash layer (C) Pore (D) None of these

Description : If a solid-gas non-catalytic reaction occurs at very high temperature, the rate controlling step is the __________ diffusion. (A) Film (B) Ash layer (C) Pore (D) None of these

Last Answer : (A) Film

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)

Which method, vapor phase oxidation or direct-melt process, transforms deposited material into a solid glass preform by heating the porous material without melting?

Description : Which method, vapor phase oxidation or direct-melt process, transforms deposited material into a solid glass preform by heating the porous material without melting?

Last Answer : Vapor phase oxidation.

In Biot number, the characteristic length used is the ratio of the __________ of the solid. (A) Volume to surface area (B) Perimeter to surface area (C) Surface area to volume (D) Surface area to perimeter

Description : In Biot number, the characteristic length used is the ratio of the __________ of the solid. (A) Volume to surface area (B) Perimeter to surface area (C) Surface area to volume (D) Surface area to perimeter

Last Answer : (A) Volume to surface area

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 neutral stress in a soil mass is (A) Force per neutral area (B) Force per effective area (C) Stress taken up by the pore water (D) Stress taken up by solid particles

Description : The neutral stress in a soil mass is (A) Force per neutral area (B) Force per effective area (C) Stress taken up by the pore water (D) Stress taken up by solid particles

Last Answer : Answer: Option C

A first order gaseous phase reaction is catalysed by a non-porous solid. The kinetic rate constant and the external mass transfer co-efficients are k and kg respectively. The effective rate constant (ke ff) is given by (A) ke ff = k + kg (B) ke ff = (k+ kg )/2 (C) ke ff = (kkg ) 1/2 (D) 1/ke ff = 1/k + 1/kg

Description : A first order gaseous phase reaction is catalysed by a non-porous solid. The kinetic rate constant and the external mass transfer co-efficients are k and kg respectively. The effective rate constant (ke ff) is given by (A) ke ff = k + kg ( ... + kg )/2 (C) ke ff = (kkg ) 1/2 (D) 1/ke ff = 1/k + 1/kg

Last Answer : (D) 1/ke ff = 1/k + 1/kg

What is the Thiele modulus of the solid catalysed first order reaction as shown in the bellow figure, if the pore diffusion offers negligible resistance to reaction? (A) < 5 (B) < 0.5(C) > 1 (D) 5

Description : What is the Thiele modulus of the solid catalysed first order reaction as shown in the bellow figure, if the pore diffusion offers negligible resistance to reaction? (A) < 5 (B) < 0.5 (C) > 1 (D) 5

Last Answer : (B) < 0.5

Which one is the rate controlling step in a solid-gas non-catalytic reaction occurring at very high temperature? (A) Pore diffusion (B) Film diffusion (C) Ash layer diffusion (D) Chemical reaction

Description : Which one is the rate controlling step in a solid-gas non-catalytic reaction occurring at very high temperature? (A) Pore diffusion (B) Film diffusion (C) Ash layer diffusion (D) Chemical reaction

Last Answer : (B) Film diffusion

The capacity of a classifier in 'tons of solid/hr' is given by (where, A = cross-sectional area in m2 , V = rising velocity of fluid in m/sec, S = percentage of solids in the suspension by volume, ρ = density of solids in kg/m3 ) (A) 3.6 AVS.ρ (B) 3.6 A.V.ρ (C) 3.6 A.S. ρ (D) 3.6 AVS/ρ

Description : The capacity of a classifier in 'tons of solid/hr' is given by (where, A = cross-sectional area in m2 , V = rising velocity of fluid in m/sec, S = percentage of solids in the suspension by volume, ρ = density of solids in kg/m3 ) (A) 3.6 AVS.ρ (B) 3.6 A.V.ρ (C) 3.6 A.S. ρ (D) 3.6 AVS/ρ

Last Answer : (A) 3.6 AVS.ρ

For a solid catalysed chemical reaction, the effectiveness of solid catalyst depends upon the __________ adsorption. (A) Physical (B) Chemical (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : For a solid catalysed chemical reaction, the effectiveness of solid catalyst depends upon the __________ adsorption. (A) Physical (B) Chemical (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (B) Chemical

Which of the following is not a unit of reaction rate? (A) Moles for med/(surface of catalyst) (time) (B) Moles formed/volume of reactor) (time) (C) Mole formed/volume of catalyst) (time) (D) None of these

Description : Which of the following is not a unit of reaction rate? (A) Moles for med/(surface of catalyst) (time) (B) Moles formed/volume of reactor) (time) (C) Mole formed/volume of catalyst) (time) (D) None of these

Last Answer : (D) None of these

Volume of `N_(2)` at 1 atm, 273 K required to form a monolayer on the surface of iron catalyst is `8.15ml//gm` of the adsorbent. What will be the surf

Description : Volume of `N_(2)` at 1 atm, 273 K required to form a monolayer on the surface of iron catalyst is `8.15ml//gm` of the adsorbent. What will be the surf

Last Answer : Volume of `N_(2)` at 1 atm, 273 K required to form a monolayer on the surface of iron catalyst is `8.15ml//gm` ... C. `39 m^(2)//g` D. `22400 cm^(2)`

For shear strength, triaxial shear test is suitable because (A) It can be performed under all three drainage conditions (B) Precise measurement of the pore pressure and volume change during the test is possible (C) Stress distribution on the failure plane, is uniform (D) All the above

Description : For shear strength, triaxial shear test is suitable because (A) It can be performed under all three drainage conditions (B) Precise measurement of the pore pressure and volume change during the test is possible (C) Stress distribution on the failure plane, is uniform (D) All the above

Last Answer : (D) All the above

A triaxial shear test is preferred to direct shear test, because (A) It can be performed under all three drainage conditions with complete control (B) Precise measurement of pore pressure and change in volume during test, is not possible (C) Stress distribution on the failure plane, is non uniform (D) None of these

Description : A triaxial shear test is preferred to direct shear test, because (A) It can be performed under all three drainage conditions with complete control (B) Precise measurement of pore pressure and change in ... possible (C) Stress distribution on the failure plane, is non uniform (D) None of these

Last Answer : Answer: Option A

If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is – (1) Height of the liquid column (2) Surface area of the bottom of the vessel (3) Density of the liquid (4) Acceleration due to gravity at the bottom of the vessel

Description : If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is – (1) Height of the liquid column (2) Surface area of the bottom of the vessel (3) Density of the liquid (4) Acceleration due to gravity at the bottom of the vessel

Last Answer : (2) Surface area of the bottom of the vessel Explanation: The pressure exerted by a static fluid depends only upon the depth of the fluid, the density of the fluid, and the acceleration of gravity. Static fluid pressure does not depend on the shape, total mass, or surface area of the liquid.

If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is – (1) Height of the liquid column (2) Surface area of the bottom of the vessel (3) Density of the liquid (4) Acceleration due to gravity at the bottom of the vessel

Description : If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is – (1) Height of the liquid column (2) Surface area of the bottom of the vessel (3) Density of the liquid (4) Acceleration due to gravity at the bottom of the vessel

Last Answer : (2) Surface area of the bottom of the vessel Explanation: The pressure exerted by a static fluid depends only upon the depth of the fluid, the density of the fluid, and the acceleration of gravity.

If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is (1) Height of the liquid column (2) Surface area of the bottom of the vessel (3) Density of the liquid (4) Acceleration due to gravity at the bottom of the vessel

Description : If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is (1) Height of the liquid column (2) Surface area of the bottom of the vessel (3) Density of the liquid (4) Acceleration due to gravity at the bottom of the vessel

Last Answer : Surface area of the bottom of the vessel

Pore size of the molecular sieve 5A is __________ mm. (A) 5 (B) 0.5 (C) 0.05 (D) 50

Description : Pore size of the molecular sieve 5A is __________ mm. (A) 5 (B) 0.5 (C) 0.05 (D) 50

Last Answer : (B) 0.5

Number of particles in a crushed solid sample is given by (where, m = mass of particles in a sample, Vp = volume of one particle, ρ= density of particles) (A) m/ρ . Vp (B) m . ρ/Vp (C) m . Vp /ρ (D) Vp /m . ρ

Description : Number of particles in a crushed solid sample is given by (where, m = mass of particles in a sample, Vp = volume of one particle, ρ= density of particles) (A) m/ρ . Vp (B) m . ρ/Vp (C) m . Vp /ρ (D) Vp /m . ρ

Last Answer : (A) m/ρ . Vp

The volume of a certain rectangular solid is 8 cm^3. Its total surface area is 32 cm^2 and its three dimensions are in geometric progression. -Maths 9th

Description : The volume of a certain rectangular solid is 8 cm^3. Its total surface area is 32 cm^2 and its three dimensions are in geometric progression. -Maths 9th

Last Answer : (b) 32 Let the edges of the solid be a, ar, ar2. Then, Volume = a x ar x ar2 = a3r3 = (ar)3. Given (ar)3 = 8 ⇒ ar = 2 Also, surface area = 2(a x ar + ar x ar2 + a × ar2) = 2(a2r + ... Given, 2ar (a + ar + ar2) = 32 ⇒ 4(a + ar + ar2) = 32 ; Sum of lengths of all edges = 32.

What is the surface area and volume of each solid below?

Description : What is the surface area and volume of each solid below?

Last Answer : what is the surface area and volume of each solid below

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

(A) Measures the catalyst surface area directly (B) Operates at very high pressure (C) Is made entirely of stainless steel (D) None of these

Description : BET apparatus (A) Measures the catalyst surface area directly (B) Operates at very high pressure (C) Is made entirely of stainless steel (D) None of these

Last Answer : (D) None of these