What does the effectiveness of the catalyst in the initiation process of anionic polymerization depend on?

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

The ease of anionic polymerization is dependent only on the catalyst system used for a given monomer. State true or false.

A

true

B

false

Which of the following can assist as a catalyst in anionic polymerization?

A

Sulphuric acid

B

Boron trifluoride

C

grignard reagent

D

all of the mentioned

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

When a discrete time LTI system is said to be causal? must not depend on x for k>n b) Output y must not depend on x for k=n c) Output y must not depend on x for kn

A

Output y must not depend on x for k>n

B

n

C

n

D

n

_________ is usually anionic if it has any charge and may contribute to anionic trash.

A

Dispersant

B

Flocculation

C

De-flocculation

D

Pith

How is the rate of polymerization dependent on the concentration of catalyst in cationic polymerization?

A

proportional to first power

B

proportional to half power

C

proportional to second power

D

no dependence

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 is rate controlling. The effectiveness factor of the catalyst is reported as $$\frac{7}{8}$$. Which of the following statement is true?

A

Inner catalyst core of radius $$\frac{{\text{R}}}{8}$$ does not participate in reaction

B

Inner catalyst core of radius $$\frac{{\text{R}}}{2}$$ does not participate in reaction

C

Inner catalyst core of radius $$\frac{{7{\text{R}}}}{8}$$ does not participate in reaction

D

Effectiveness factor for a zero order reaction can not be $$\frac{7}{8}$$ as it must always be 1

How the termination in anionic polymerization most probably does take place?

A

unimolecular termination

B

bimolecular

C

termination by solvent transfer

D

all of the mentioned

Determine the correctness or otherwise of the following Assertion (A) and the Reason (R).
Assertion: Somatic embryogenesis in plants is a twostep process comprising of embryo initiation followed by embryo production.
Reason: Embryo initiation is independent of the presence of 2, 4-dichlorophenoxyacetic acid, whereas embryo production requires a high concentration of 2, 4-dichlorophenoxyacetic acid.

A

Both (A) and (R) are true and (R) is the correct reason for (A)

B

Both (A) and (R) are true and (R) is not the correct reason for (A)

C

(A) is true but (R) is false

D

(A) is false but (R) is true

What does the effectiveness of the catalyst in the initiation process of anionic polymerization depend on?

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