Free Chemical Reaction Engineering MCQs with Answers

• A. Causes olefins to combine with each other
• B. Converts iso-paraffin into olefin
• C. Causes olefins to combine with iso-paraffins
• D. Converts olefin into paraffin

Explanation: In petroleum alkylation, an olefin combines with an iso-paraffin such as isobutane to form a higher-molecular-weight, highly branched…

• A. None of these
• B. Increases the rate of reaction
• C. Produces high octane number gasoline
• D. Increases coke formation

Explanation: In catalytic reforming, higher pressure favours hydrogenation and suppresses coke deposition, while lower pressure generally promotes…

• A. Catalytic naphtha - coking naphtha - virgin naphtha
• B. Coking naphtha - virgin naphtha - catalytic naphtha
• C. Virgin naphtha - catalytic naphtha - coking naphtha
• D. Virgin naphtha - coking naphtha - catalytic naphtha

Explanation: The usual preference listed for catalytic-reformer feed is coking naphtha, followed by virgin naphtha and then catalytic naphtha.

• A. Stabilisation
• B. Visbreaking
• C. Cracking
• D. Reforming

Explanation: Petroleum coke is produced by coking, particularly delayed coking, in which heavy residues undergo severe thermal cracking and leave a…

• A. 80
• B. 87
• C. 92
• D. 97

Explanation: Two-stage fluidised catalytic cracking gives a highly upgraded gasoline, with an octane number commonly quoted near 97.

• A. Cracked gases rich in C2 & C4 olefins
• B. Naphtha
• C. Low boiling aromatics
• D. None of these

Explanation: Polymerisation units use olefin-rich cracked gases, especially light olefins such as ethylene and butylene, as feedstock.

• A. Gives higher yield of petrol
• B. Lower octane number of petrol
• C. Higher sulphur content in the product
• D. Higher gum forming material in petrol

Explanation: Catalytic cracking converts heavy petroleum fractions into more gasoline-range products and generally gives a higher gasoline yield than…

• A. Dubbs process
• B. T.C.C. moving bed process
• C. Fluidised bed catalytic cracking process
• D. Houdry's fixed bed process

Explanation: Fluidised-bed catalytic cracking, or FCC, is the dominant modern refinery cracking process because its continuously circulating catalyst…

• A. Coke
• B. Lube oil
• C. Petrolatum
• D. Gasoline

Explanation: Cracking breaks large hydrocarbon molecules into smaller, more valuable molecules, with gasoline being the principal desired product.

• A. Uses natural gas as feed
• B. Produces fuel oil of lower viscosity
• C. Is carried out at atmospheric pressure
• D. Produces gasoline only

Explanation: Visbreaking is a mild thermal cracking treatment of heavy petroleum fractions that reduces the viscosity of the resulting residual fuel…

• A. H2SO4
• B. H3PO4
• C. Both A. and B.
• D. AlCl3

Explanation: Catalytic polymerisation of light olefins to polymer gasoline has been carried out using either sulphuric acid or phosphoric acid…

• A. Ethane
• B. Ethyl alcohol
• C. Methane
• D. Methyl alcohol

Explanation: MTBE is formed by acid-catalysed addition of methanol to isobutylene: isobutylene plus methyl alcohol gives methyl tertiary butyl ether.

• A. Dehydrogenation of naphthenes
• B. Hydrogenation of naphthenes
• C. Hydrocracking of paraffins
• D. Saturation of olefins

Explanation: Catalytic reforming raises octane mainly by converting naphthenes into aromatic hydrocarbons with release of hydrogen, a dehydrogenation…

• A. 85
• B. 65
• C. 50
• D. 98

Explanation: Catalytic reforming of naphtha normally gives a high reformate or gasoline yield, commonly around 80 to 90 percent by weight.

• A. Lighter paraffins
• B. Olefins and aromatics
• C. Stabilised gasoline
• D. Diesel

Explanation: Pyrolysis cracks kerosene or natural gasoline at high temperature into smaller unsaturated molecules and ring compounds, producing mainly…

• A. Alumina
• B. Nickel
• C. Silica gel
• D. Sulphuric acid

Explanation: Sulphuric acid is a liquid acid catalyst commonly used in alkylation to combine light olefins with isoparaffins.

• A. An endothermic reaction
• B. An exothermic reaction
• C. Favoured at very low temperature
• D. None of these

Explanation: Cracking breaks large hydrocarbon molecules into smaller ones and requires heat to rupture their bonds, so it is endothermic.

• A. Less than 90% promotes polymerisation
• B. Both A. and B.
• C. More than 98% promotes cracking
• D. Neither A. nor B.

Explanation: Acid that is too dilute, below about 90%, encourages polymerisation of olefins, while excessively concentrated acid can promote…

• A. H2SO4
• B. H3PO4
• C. AlCl3
• D. HF

Explanation: Aluminium chloride, usually with hydrogen chloride, is the classical catalyst system for hydrocarbon isomerisation.

• A. Olefins into paraffins
• B. Naphthenes into paraffin
• C. Naphthenes into olefins
• D. Naphthenes into aromatics

Explanation: In catalytic reforming, cycloalkanes or naphthenes undergo dehydrogenation to form aromatic hydrocarbons, often with hydrogen as a…