Chemical Engineering MCQs

“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?A. Inner catalyst core of radius R/8 does not participate in reaction.”

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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
Ffectiveness factor for a zero order reaction can not be 7/8 as it must always be 1
✅ The correct answer is option A.

During manufacture of H₂SO₄, the oxidation of SO₂ to SO₃ by oxygen is an en- dothermic reaction. The yield of SO₃ will be maximised, if the

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Temperature is increased
Pressure is reduced
Temperature is increased and pressure is reduced
Temperature is reduced and pressure is increased
✅ The correct answer is option D.

In the hydrodealkylation of toluene to benzene, the following reactions occur: C₇H₈ + H₂ → C₆H₆ + CH₄ 2C₆H₆ ⇋ C₁₂H₁₀ + H₂ Toluene and hydrogen are fed to a reactor in a molar ratio 1:5.80% of the toluene gets converted and the selectivity of benzene(defined as moles of benzene formed/moles of toluene converted) is 90%. The fractional conversion of hydrogen is

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0.16
0.144
0.152
0.136
✅ The correct answer is option B.