Chemical Engineering - Chemical Reaction Engineering

41.
Second order consecutive irreversible reactions were carried out in a constant volume isothermal batch reactor with different initial feed compositions. Reactor temperature was same in all the cases. In experiments where the ratio of concentration of B to that of A in the initial feed was less than 0.5, the concentration of B increased first, reached a maximum and then declined with time. However, for all experiments where this concentration ratio was 0.5 or above, concentration of B decreased monotonically with time right from the beginning. What is the ratio of the two rate constants (k1/k2)?
1/4
1/2
2
4
Answer: Option
Explanation:
No answer description is available. Let's discuss.

42.
Pick out the wrong statement.
Catalytic activity of enzyme catalysed reactions which is affected by temperature, pH value & chemical agents, is maximum at a temperature of about 45°C.
Most of the enzyme catalysed reactions involve at least two substrates.
Enzymes help in increasing the activation energy of the reaction.
Equilibrium concentrations in enzyme catalysed reactions can be calculated by using the thermodynamic properties of substrates & products.
Answer: Option
Explanation:
No answer description is available. Let's discuss.

43.
There is no correspondence between stoichiometry and the rate equation in case of a/an __________ reaction.
elementary
multiple
autocatalytic
non-elementary
Answer: Option
Explanation:
No answer description is available. Let's discuss.

44.
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 7/8. Which of the following statement is true?
Inner catalyst core of radius R/8 does not participate in reaction.
Inner catalyst core of radius R/2 does not participate in reaction.
Inner catalyst core of radius 7R/8 does not participate in reaction.
Effectiveness factor for a zero order reaction can not be 7/8 as it must always be 1.
Answer: Option
Explanation:
No answer description is available. Let's discuss.

45.
Which of the following is used for calcination of limestone and dolomite in industrial practice ?
Fluidised bed reactor
Moving bed reactor
Fixed bed reactor
None of these
Answer: Option
Explanation:
No answer description is available. Let's discuss.