Unit Processes Multiple Choice Questions on “Preparations”.
1. The losses incidental to the neutralization of the nitrobenzene are directly proportional to what?
a) Number of washes given
b) The amount of water used
c) All of the mentioned
d) None of the mentioned
Answer: c
Clarification: In loss in Wash Waters, the losses incidental to the neutralization of the nitrobenzene are directly proportional to the number of washes given and the amount of water used.
2. What percent of nitric acid is added to the nitrator to produce a mixed acid during the process of continuous nitration with fortified spent acid?
a) 4%
b) 63%
c) 36%
d) 45%
Answer: b
Clarification: During vigourous agitation in continous nitration for the production of nitrobenzene, sufficient 63 percent nitric acid is added to the nitrator to produce a mixed acid containing 4 per cent HNO3.
3. What is the formula of m-Dinitro benzene?
a) (1,3)-Dinitrobenzene
b) (1,2)-Dinitrobenzene
c) (1,4)-Dinitrobenzene
d) (1,5)-Dinitrobenzene
Answer: a
Clarification: ‘m’ stands for ‘meta’, and it’s position is 3rd Carbon on the benzene ring, whereas 2 and 4 are ortho and para respectively.
4. For preparation of Chloro-nitrobenzene which of the following position gives highest amount?
a) Ortho
b) Meta
b) Para
d) All of the mentioned
Answer: a
Clarification: For the production of Chloro-nitrobenzene we get 66.9% at ortho position and 33.1% at para position.
5. Complete the above reaction: C6H5CH3 + 18H2SO4 + 18HNO3 ——–> ____ HNOSO4 + 7CO2 + 22H2O
a) 16
b) 17
c) 18
d) 19
Answer: c
Clarification: To balance the above reaction we get : C6H5CH3 + 18H2SO4 + 18HNO3 —–> 18HNOSO4 + 7CO2 + 22H2O.
6. What is used for the production if dyes and isocyanates?
a) Nitrotoluenes
b) Toluene
c) Phenol
d) Amines
Answer: a
Clarification: The nitrotoluenes are used primarily as intermediates in the dye industry and the toluene diamines derived from dinitrotoluenes are used as intermediates for the production of isocyanates.
7. When naphthalene is nitrated under optimal conditions, what product do we get?
a) a(alpha)-nitrotoluene
b) b(beta)-nitrotoluene
c) (gamma)-nitrotoluene
d) all of the mentioned
Answer: a
Clarification: When naphthalene is nitrated under optimal conditions, the product consists principally of a-nitronaphthalene. The reaction takes place vigorously; and unless precautions are taken, polynitro compounds are formed.
8. The purification of products, during the formation of a(alpha)-nitronaphthalene , depends upon the following ____________
a) Use of minimum solvent
b) Constant agitation
c) All of the mentioned
d) None of the mentioned
Answer: d
Clarification: The purification of the crude product is accomplished also by recrystallization. The success of the purification depends upon certain details of manipulator which include (1) use of a minimum of solvent and (2) constant agitation while recrystallization takes place in order to assure the formation of crystals.
9. In which column the crude nitroparaffins and water are stripped out of the solvent, during the “preparation of Nitroparaffins”?
a) Distillation column
b) Absorbing column
c) Stripping column
d) None of the mentioned
Answer: c
Clarification: During the processing of Nitroparaffins, the liquid phase from the absorber is transferred to the top of a steam-heated column called the stripper in which the crude nitroparaffins and water are stripped out of the solvent.
10. During the process of nitration of propane, the main production of nitroparaffins include what ?
a) Nitromethane
b) Nitro ethane
c) 1-nitropropane
d) All of the mentioned
Answer: d
Clarification: By the process of nitration of propane, the main production of nitroparaffins includes nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane. The nitration is done in the vapor phase.