Related Questions

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
Effectiveness factor (E) of a catalyst pellet is defined as, E = (actual rate within pore of catalyst/rate if notsnowed 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
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
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 of the above
A catalyst is said to be a negative catalyst, ifit
A Retards the rate of reaction
B Reduces the value of equilibrium constant
C Does not initiate the reaction
D All of the above
For the hydrogenation of oils (i) __________ is commonly used as catalyst and (ii) __________ is a catalyst poison.
A (i) platinum (ii) sulphur
B (i) palladium (ii) oxygen
C (i) nickel (ii) sulphur
D (i) nickel (ii) oxygen
Which of the following is added in low carbon steels to prevent them from becoming porous?
A Sulphur
B Phosphorus
C Manganese
D Silicon
Molecular seives are porous
A Alumina
B Silica
C Synthetic zeolites crystals/metal alumino-silicates
D None of these
Thermocole is a spongy, porous, rigid or flexible foamed plastic, obtained by blowing gas/air through molten
A Saturated polyester
B Polyurathane
C Polystyrene
D Either B or C
For preparation of porous bearings by powder metallurgy, preferred particle shape is
A Spherical
B Nodular
C Irregular
D No preferred shape

Next steps