Engineering Questions with Answers - Multiple Choice Questions
Unit Processes MCQ’s – Aromatic Hydrocarbon Oxidation
1 - Question
Why is controlled oxidation needed?
a) High energy
b) Loss of products
c) Temperature
d) All of the mentioned
View Answer
Explanation: In the majority of cases, steps must be taken to limit the extent of the reaction and prevent complete loss of product through continued oxidation.
2 - Question
In which phase is Oxidation of high molecular weight done?
a) Vapour
b) Liquid
c) Solid
d) None of the mentioned
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Explanation: Oxidations are conducted in the liquid phase in cases where high-molecular-weight, complex, and more or less thermally unstable substances are dealt with and where the oxidizing agent is relatively non-volatile.
3 - Question
Extent of oxidation can be controlled by?
a) Oxidizing agent
b) Duration of reaction
c) Temperature control
d) All of the mentioned
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Explanation: Temperatures are low or moderate, and the extent of oxidation may be readily controlled by (1) limiting the duration of operation, (2) controlling the temperature, and (3) limiting the amount of oxidizing agent.
4 - Question
Vapour phase oxidation can be readily effective to which type of compound?
a) Volatile
b) Non-volatile
c) Both volatile and non-volatile
d) None of the mentioned
View Answer
Explanation: Vapour-phase oxidation reactions can be effectively applied only to readily volatile substances that are of sufficient thermal stability to resist dissociation at elevated temperatures.
5 - Question
Control in oxidation processes can be done by?
a) Time
b) Temperature
c) Catalyst
d) All of the mentioned
View Answer
Explanation Control is effected by limiting the time of contact, temperature, proportion of oxygen, or type of catalyst or by combinations of these factors.
6 - Question
Is oxidation of the low-molecular-weight paraffin hydrocarbons under high pressures possible?
a) No
b) Yes
View Answer
Explanation: By conducting the oxidation of the low-molecular-weight paraffin hydrocarbons under high pressures it has been possible to obtain alcohols, increased yields of aldehydes, and acids as oxidation products. Conditions claimed for the pressure processes include (1) pressures of 50-250 atm, (2) temperatures from 200-600°C, (3) low oxygen: hydrocarbon ratios ranging from 5-15 moles per cent, (4) short time of contact, and (5) the presence.
7 - Question
Noncatalytic oxidation of the aromatic hydrocarbons is slow at which temperature?
a) Above 800
b) Below 800
c) Below 500
d) Above 500
View Answer
Explanation: Noncatalytic oxidation of the aromatic hydrocarbons is slow at temperatures below 500°C.
8 - Question
Removal of energy during reaction leads to what?
a) Completion of reaction
b) Limit the reaction
c) All of the mentioned
d) None of the mentioned
View Answer
Explanation: Equilibrium is favourable, and the problems are largely the removal of heat at the desired reaction temperature level and the limitation of the oxidation to the desired product by avoidance of complete combustion.
9 - Question
Catalyst are also used to direct the reaction towards desired product.
a) True
b) False
View Answer
Explanation: Catalysts are generally used in an effort to obtain the oxidation reaction at the Iowest temperature as possible and to direct the reaction to the desired products.