Unit Processes Multiple Choice Questions on “Manufacturings”.
1. Alkyd resins are polymeric esters are heated with what?
a) Basic acid
b) Dibasic acid
c) Tribasic acid
d) All of the mentioned
Answer: b
Clarification: Alkyd resins are polymeric esters which are obtained when polyhydric alcohols are heated with dibasic acids.
2. The Dibasic acids are usually the crude acid mixtures.
a) True
b) False
Answer: b
Clarification: The monobasic acids are usually the crude acid mixtures that are obtained by saponifying natural oils, such as linseed, soybean, castor, or cottonseed oils.
3. How is diffusion in mixtures which are viscous at start?
a) Fast
b) Mild
c) Slow
d) None of the mentioned
Answer: c
Clarification: Diffusion is slow in these mixtures which are fairly viscous at the start and become much more so toward the end.
4. Which type of catalyst are used in manufacture of Alkyd Resins?
a) Lead
b) Zinc chloride
c) Triphenyl phosphite
d) All of the mentioned
Answer: d
Clarification: A wide variety of catalysts, such as lead, calcium, zinc, phosphoric acid, zinc chloride, triphenyl phosphite, and ptoluenesulfonic acid, have been used for the manufacturing of alkyl resins.
5. What happens to the rate of heating as kettle size increases?
a) Increases
b) Decreases
c) No change
d) None of the mentioned
Answer: b
Clarification: As the kettle size is increased, the rate of heating up the contents of the kettle is lowered, because of the diminishing ratio of heating surface to the weight of the charge in the kettle.
6. Why is agitation in reaction kettle necessary?
a) Immiscible reactants
b) Viscosity
c) Both immiscible reactant and viscosity
d) None of the mentioned
Answer: c
Clarification: Thorough agitation in the reaction kettle is a necessity because of the immiscibility of the ingredients and the viscosity of the mixtures.
7. Terpene esters can be made by the direct addition of fatty acids only.
a) True
b) False
Answer: b
Clarification: Terpene esters can be made by the direct addition of fatty acids and halogenated and thiocyanated fatty acids to terpene hydrocarbons, ethers, and esters.
8. The bicyclic terpenes are more reactive than what?
a) Monocyclic terpenes
b) Tricyclic terpenes
c) Both mono and tricyclic terpenes
d) None of the mentioned
Answer: a
Clarification: Since the bicyclic terpenes (camphene, a-pinene, and fl-pinene) are more reactive than the monocyclic, they are the preferable starting materials.
9. Cellulose acetate is used in manufacturing of what?
a) Cellulose acetate yarn
b) Plastics
c) Photographic films
d) All of the mentioned
Answer: d
Clarification: Cellulose acetate is an important commercial polymer used in the manufacture of cellulose acetate yarn, plastics, photographic films and sheeting, and surface coatings.
10. Cellulose occurs in which type of polymer weight?
a) Low molecular weight
b) Moderate
c) High molecular weight
d) None of the mentioned
Answer: c
Clarification: Cellulose occurs in these materials as a fairly highly crystalline, high-molecular-weight polymer. It is in a fibrous form, which is insoluble in common reagents.
11. The reaction of an alkali cellulose with carbon disulphide produces what?
a) Cellulose xanthate
b) Cellulose sulphide
c) Sulphide xanthate
d) None of the mentioned
Answer: a
Clarification: The reaction of an alkali cellulose with carbon disulphide to form cellulose xanthate.