Practice Pakistan's most useful MCQs for competitive exams

In a/an _____________ vessel, the fluid enters and leaves following plug flow?

• (A)  Open
• (B)  Closed
• (C)  Open-closed
• (D)  Close-opened

Answer

Submitted By :Ali Uppal

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

Answer

Submitted By :Ali Uppal

Carbon particles accumulated on the catalyst used in the gas oil cracking lies in the category of _____________________ poison?

• (A)  Deposited
• (B)  Chemisorbed
• (C)  Selectivity
• (D)  Stability

Answer

Submitted By :Ali Uppal

In a reversible reaction, a catalyst increases the rate of forward reaction__________________?

• (A)  Only
• (B)  To a greater extent than that of the backward reaction
• (C)  And decreases that of the backward reaction
• (D)  And the backward reaction equally

Answer

Submitted By :Ali Uppal

In an ideal mixed reactor (at steady state), the ___________________?

• (A)  Space time is equivalent to holding time for constant density systems
• (B)  Composition throughout the reactor remains same
• (C)  Exit stream has the same composition as the fluid within the reactor
• (D)  All

Answer

Submitted By :Ali Uppal

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

Answer

Submitted By :Ali Uppal

A gaseous reactant is introduced in a mixed reactor of 3 litres volume at the rate of 1 litre/second. The space time is ______________ seconds?

• (A)  1
• (B)  3
• (C)  1/3
• (D)  32

Answer

Submitted By :Ali Uppal

With increase in initial concentration, the fractional conversion of a first order reaction in a given time___________________?

• (A)  Increases
• (B)  Decreases
• (C)  Remain constant
• (D)  Unpredictable

Answer

Submitted By :Ali Uppal

The molecularity and the order of reaction respectively, for the hydrolysis of methyl acetate in presence of acids are_______________?

• (A)  2 & 1
• (B)  11 & 2
• (C)  2 & 2
• (D)  1 & 1

Answer

Submitted By :Ali Uppal

Which one is the rate controlling step in a solid-gas non-catalytic reaction occurring at very high temperature ?

• (A)  Pore diffusion
• (B)  Film diffusion
• (C)  Ash layer diffusion
• (D)  Chemical reaction

Answer

Submitted By :Ali Uppal