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)
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
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
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
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 BrunauerEmmett-Teller (BET) technique
Last Answer : (A) A lower temperature favours the reaction of lower activation energy
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
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
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
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
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)
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)
Description : A spherical porous catalyst particle of radius R is subjected to reactant A which reacts to form B by a zero order surface reaction A → B. Film mass transfer resistance is negligible and pore diffusion of A ... (D) Effectiveness factor for a zero order reaction cannot be 7/8 as it must always be 1
Last Answer : (A) Inner catalyst core of radius R/8 does not participate in reaction (
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
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
Description : Bulk diffusion in catalyst pore __________ with increase in pressure. (A) Increases (B) Decreases (C) Remains unchanged (D) Increases exponentially
Last Answer : (B) Decreases
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
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
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
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
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
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
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
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
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'
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
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
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)`
Description : Thermal conductivity of a conducting solid material depends upon its (A) Temperature (B) Porosity (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
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
Description : Measurement of the interfacial area of mass transfer is achieved easily & accurately in case of a __________ column. (A) Spray (B) Packed (C) Bubble cap plate (D) Wetted wall
Last Answer : (D) Wetted wall
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
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
Description : Which are the only two elements on the periodic table that are liquid at room temperature? A. Mercury and Bromine (Answer) B. Carbon and helium C. Nitrogen and Hydrogen D. Oxygen and Neon
Last Answer : A. Mercury and Bromine (Answer)
Description : Most commercial nuclear power plants worldwide are cooled by: w) sodium x) mercury y) helium z) water
Last Answer : ANSWER: Z -- WATER
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
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
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
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)
Description : Furnace aerodynamics is related to the __________ in the furnace. (A) Movement of gases (B) Measurement of flue gas volume (C) Temperature control
Last Answer : (A) Movement of gases
Description : All the atoms of the world comprise of electrons, proton & neutron except that of __________ atom in which neutron is absent. (A) Deuterium (B) Hydrogen (C) Neon (D) Helium
Last Answer : (B) Hydrogen
Description : PROBLEM FA sample of soft saturated clay weighs 350 grams and has a volume of 205cc. After oven drying, the soil weighs 225 grams. Calculate the values of saturated unit weight, void ratio, porosity and specific gravity?
Last Answer : {
Description : Pick up the correct statement from the following: (A) The volume of underground water extracted by gravity drainage from a saturated soil, is known as yield (B) The ratio of volume ... ) The sum of specific yield and specific retention, is equal to porosity (D) All the above
Description : The ratio of the weight of given volume of soil solids to the weight of an equal volume of distilled water at the given temperature, is known (A) Porosity (B) Specific gravity (C) Void ratio (D) Water content
Last Answer : (B) Specific gravity
Description : The ratio of the volume of voids to the volume of soil solids in a given soil mass, is known (A) Porosity (B) Specific gravity (C) Void ratio (D) Water content
Last Answer : (C) Void ratio
Description : The ratio of volume of voids to the total volume of soil mass is called (A) Air content (B) Porosity (C) Percentage air voids (D) Voids ratio
Last Answer : (B) Porosity
Description : If the volume of voids is equal to the volume of solids in a soil mass, then the values of porosity and voids ratio respectively are (A) 1.0 and 0.0 (B) 0.0 and 1.0 (C) 0.5 and 1.0 (D) 1.0 and 0.5
Last Answer : (C) 0.5 and 1.0
Description : The ratio of the volume of voids to the total volume of the given soil mass, is known (A) Porosity (B) Specific gravity (C) Void ratio (D) Water content
Last Answer : (A) Porosity
Description : The ratio of the volume of water present in a given soil mass to the total volume of its voids, is known (A) Porosity (B) Void ratio (C) Percentage voids (D) Degree of saturation
Last Answer : Answer: Option D
Description : The property of a soil which allows it to be deformed rapidly without rupture, elastic rebound and also a volume change, is known (A) Porosity (B) Plasticity (C) Permeability (D) Ductility
Last Answer : Answer: Option B