Engineering Questions with Answers - Multiple Choice Questions
Chemical Technology MCQ’s – C3 Compounds – Oxo Process
1 - Question
What is an oxo process?
a) Substitution of H-CHO across a double bond
b) Addition of H-CHO across a double bond
c) Substitution of H-CHO across a triple bond
d) Addition of H-CHO across a triple bond
Explanation: An oxo process involves substitution of H-CHO across a double bond, hence the name hydroformylation. The reactants are synthesis gas and an olefin.
2 - Question
What are the suitable thermodynamics in an oxo process?
a) High temperature and pressure
b) Low temperature and pressure
c) High temperature low pressure
d) Low temperature high pressure
Explanation: The reaction yield should be best at a low temperature and high pressure. Higher pressure is used since cobalt carbonyl is involved in the reaction mechanism which can only form at high pressure.
3 - Question
What is the final product of an oxo process?
d) Aldehyde with one additional C atom
Explanation: The reactants involved in oxo process are an olefin and synthesis gas (CO+H2). The primary product is an aldehyde with an additional C atom. It’s a twostep process consisting of an addition reaction followed by dimerization.
4 - Question
Cobalt carbonyl is soluble in the hydrocarbons during the manufacture of oxo process.
Explanation: Cobalt carbonyl is soluble in the hydrocarbon’s liquids so the cobalt on the catalyst surface would soon be stripped. This is avoided by adding soluble Co naphthenate, but the metal ion must be removed in the decobalting unit, otherwise metallic sludge forms in the equipment.
5 - Question
Decobalting is not a process alternative in oxo process.
Explanation: Hydrogen gas at low pressure can be used instead of superheated steam to deposit the cobalt. Hence it can be used as an alternative.
6 - Question
What are the steps involved in the manufacture of butanol by oxo process?
a) Aldehyde step-Alcohol step
b) Aldehyde step-Acid step
c) Acid step-Alcohol step
d) Ketone step-Alcohol step
Explanation: The process starts with an aldehyde step in which forms an aldehyde which further gets converted to alcohol by the addition of hydrogen with Ni catalyst.