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

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
by

1 Answer

Answer :

(A) Specific surface of a porous catalyst
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

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

. 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)

Description : . 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)

Last Answer : (C) Surface area

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)

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)

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)

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

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)

A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 × 10 3 VOM + 10.94 × 10 6 V2 OM (SI units) If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s

Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle ... fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s

Last Answer : (B) 16 mm/s

A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below: Δ P/L = 375 × 10 3 VOM + 10.94 × 10 6 V2 OM (SI units) If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8

Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system ... What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8

Last Answer : (C) 0.7

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

Bed pressure drop in an air fluidised bed of catalyst particles (ρp = 200 kg/m3, Dp = 0.05 cm) of 60 cm bed depth and bed porosity of 0.5 expressed in cm of water (manometer) is (A) 90 (B) 60 (C) 45 (D) 30

Description : Bed pressure drop in an air fluidised bed of catalyst particles (ρp = 200 kg/m3, Dp = 0.05 cm) of 60 cm bed depth and bed porosity of 0.5 expressed in cm of water (manometer) is (A) 90 (B) 60 (C) 45 (D) 30

Last Answer : (B) 60

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

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

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

A coalescer in a mixer-settler liquid-liquid extraction column (A) Comprises of thin bed of substances of extended surface having high porosity (B) Helps in increasing the bubble size entering the settler (C) Helps in increasing the settling rate of the bubbles (D) All 'a', 'b', & 'c'

Description :  A coalescer in a mixer-settler liquid-liquid extraction column (A) Comprises of thin bed of substances of extended surface having high porosity (B) Helps in increasing the bubble size entering the settler ... increasing the settling rate of the bubbles (D) All 'a', 'b', & 'c'

Last Answer : (D) All 'a', 'b', & 'c'

Promoter is added to the catalyst to improve its (A) Porosity (B) Sensitivity (C) Surface area (D) None of these

Description : Promoter is added to the catalyst to improve its (A) Porosity (B) Sensitivity (C) Surface area (D) None of these

Last Answer : (B) Sensitivity

In Joule-Thomson porous plug experiment, the (A) Enthalpy does not remain constant (B) Entire apparatus is exposed to surroundings (C) Temperature remains constant (D) None of these

Description : In Joule-Thomson porous plug experiment, the (A) Enthalpy does not remain constant (B) Entire apparatus is exposed to surroundings (C) Temperature remains constant (D) None of these

Last Answer : (D) None of these

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

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)

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 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

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

A gas (density = 1.5 kg/m3 , viscosity = 2 × 10 ‒5 kg/m.s) flowing through a packed bed (particle size = 0.5 cm, porosity = 0.5) at a superficial velocity of 2 m/s causes a pressure drop of 8400 Pa/m. The pressure drop for another gas, with density of 1.5 kg/m3and viscosity of 3 × 10 ‒5kg/m.s flowing at 3 m/s will be (A) 8400 Pa/m (B) 12600 Pa/m (C) 18900 Pa/m (D) 16800 Pa/m

Description : A gas (density = 1.5 kg/m3 , viscosity = 2 10 -5 kg/m.s) flowing through a packed bed (particle size = 0.5 cm, porosity = 0.5) at a superficial velocity of 2 m/s causes a pressure drop of 8400 Pa/m. The ... flowing at 3 m/s will be (A) 8400 Pa/m (B) 12600 Pa/m (C) 18900 Pa/m (D) 16800 Pa/m

Last Answer : (B) 12600 Pa/m

For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is (A) More (B) Less (C) Equal (D) Independent of porosity

Description : For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is (A) More (B) Less (C) Equal (D) Independent of porosity

Last Answer : (B) Less

A bed consists of particles of density 2000 kg/m3 . If the height of the bed is 1.5 metres and its porosity 0.6, the pressure drop required to fluidise the bed by air is (A) 25.61 kPa (B) 11.77 kPa (C) 14.86 kPa (D) 21.13 kPa

Description : A bed consists of particles of density 2000 kg/m3 . If the height of the bed is 1.5 metres and its porosity 0.6, the pressure drop required to fluidise the bed by air is (A) 25.61 kPa (B) 11.77 kPa (C) 14.86 kPa (D) 21.13 kPa

Last Answer : (B) 11.77 kPa

Minimum porosity for fluidisation is(A) That corresponding to static bed (B) That corresponding to completely fluidised bed (C) The porosity of the bed when true fluidisation begins (D) Less than that of the' static bed

Description : Minimum porosity for fluidisation is (A) That corresponding to static bed (B) That corresponding to completely fluidised bed (C) The porosity of the bed when true fluidisation begins (D) Less than that of the' static bed

Last Answer : (C) The porosity of the bed when true fluidisation begins

The probability distribution taken to represent the completion of time in PERT analysis is (a) Normal Distribution (b) Bet Distribution (c) Gamma Distribution (d) Gaussain Distribution

Description : The probability distribution taken to represent the completion of time in PERT analysis is (a) Normal Distribution (b) Bet Distribution (c) Gamma Distribution (d) Gaussain Distribution

Last Answer : (a) Normal Distribution

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

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

The contraction (Gaseous) porosity in inlays is related to:** A. Overheating of the alloy B. Molten gases C. Diameter of the sprue D. Overheating of investment

Description : The contraction (Gaseous) porosity in inlays is related to:** A. Overheating of the alloy B. Molten gases C. Diameter of the sprue D. Overheating of investment

Last Answer : B. Molten gases

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

How can one determine the particle size distribution for a given bulk solid?

Description : How can one determine the particle size distribution for a given bulk solid?

Last Answer : While there are high-tech methods of performing such an analysis (laser-diffraction and video imaging system are available), the simplest way is to use a sieve stack. For example, to analyze a ... a combination of movements (shaken) to allow the solids to pass through the appropriate mesh sizes.

Which one is used to determine the colour of petroleum products? (A) Colour comparator (B) Saybolt chromometer (C) Cleveland apparatus (D) None of these

Description : Which one is used to determine the colour of petroleum products? (A) Colour comparator (B) Saybolt chromometer (C) Cleveland apparatus (D) None of these

Last Answer : (A) Colour comparator

Orsat apparatus(A) Gives flue gas analysis on dry basis (B) Determines N2 in flue gas indirectly (C) Can’t determine CO in flue gas, if it is < 0.2% (D) All (A), (B) & (C)

Description : Orsat apparatus (A) Gives flue gas analysis on dry basis (B) Determines N2 in flue gas indirectly (C) Can’t determine CO in flue gas, if it is < 0.2% (D) All (A), (B) & (C)

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

The rate of emission of radiation by a body does not depend upon the (A) Wavelength of radiation (B) Surface temperature of the body (C) Nature of the surface (D) Shape and porosity of the body

Description : The rate of emission of radiation by a body does not depend upon the (A) Wavelength of radiation (B) Surface temperature of the body (C) Nature of the surface (D) Shape and porosity of the body

Last Answer : (D) Shape and porosity of the body

The rate of emission of radiation by a body does not depend upon the (A) Wavelength of radiation (B) Surface temperature of the body (C) Nature of the surface (D) Shape and porosity of the body

Description : The rate of emission of radiation by a body does not depend upon the (A) Wavelength of radiation (B) Surface temperature of the body (C) Nature of the surface (D) Shape and porosity of the body

Last Answer : (D) Shape and porosity of the body

Most important factor to be considered in the selection of packings for absorbers is the __________ of packing. (A) Size (B) Durability (C) Porosity (D) Cost

Description : Most important factor to be considered in the selection of packings for absorbers is the __________ of packing. (A) Size (B) Durability (C) Porosity (D) Cost

Last Answer : (C) Porosity

Powder metallurgy is used to produce (A) High precision components with complex cavities and sharp features (B) Components of large size (C) Porosity free components (D) Components of such alloys whose constituents do not form alloys readily

Description : Powder metallurgy is used to produce (A) High precision components with complex cavities and sharp features (B) Components of large size (C) Porosity free components (D) Components of such alloys whose constituents do not form alloys readily

Last Answer : (C) Porosity free components

Segregation is responsible for (A) Honey-combed concrete (B) Porous layers in concrete (C) Surface scaling in concrete (D) All the above

Description : Segregation is responsible for (A) Honey-combed concrete (B) Porous layers in concrete (C) Surface scaling in concrete (D) All the above

Last Answer : (D) All the above

The most useless aggregate is one whose surface texture is (A) Smooth (B) Granular (C) Glassy (D) Honey combed and porous

Description : The most useless aggregate is one whose surface texture is (A) Smooth (B) Granular (C) Glassy (D) Honey combed and porous

Last Answer : (C) Glassy

Pick up the correct statement from the following: (A) According to the petrological characteristics, concrete aggregates are classified as heavy weight, normal weight and light weight (B) According to the shape of the particles, concrete aggregates are classified as rounded irregular, angular and flaky (C) According to the surface texture of the particles, the concrete aggregates are classified as glassy, smooth, granular, rough, crystalline, honey combed and porous (D) All the above

Description : Pick up the correct statement from the following: (A) According to the petrological characteristics, concrete aggregates are classified as heavy weight, normal weight and light weight (B) According to ... glassy, smooth, granular, rough, crystalline, honey combed and porous (D) All the above

Last Answer : Answer: Option D

Segregation in concrete results in (a) Honey combing (b) Porous Layers (c) Surface scaling (d) All the above

Description : Segregation in concrete results in (a) Honey combing (b) Porous Layers (c) Surface scaling (d) All the above

Last Answer : (d) All the above

. Which of the following is used as a catalyst in fluidised bed catalytic cracking? (A) Silica-magnesia (B) Silica-alumina (C) Bentonite clays (D) All (A), (B) and (C

Description : . Which of the following is used as a catalyst in fluidised bed catalytic cracking? (A) Silica-magnesia (B) Silica-alumina (C) Bentonite clays (D) All (A), (B) and (C

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