Unit Processes Multiple Choice Questions on “Aminating Agents-hydroammonolysis”.
1. The reactions involving the lower aliphatic aldehydes takes place in what phase?
a) Vapour
b) Liquid
c) Solid
d) All of the mentioned
Answer: a
Clarification: The reactions involving the lower aliphatic aldehydes usually take place in the vapor phase.
2. We get better results of hydroammonolysis in the presence of which solvent?
a) Zinc
b) Alcohol
c) Water
d) Ammonia
Answer: b
Clarification: In liquid-phase reactions, better results are generally obtained if hydro ammonolysis is carried out under pressure in the presence of an alcohol as a diluent or solvent.
3. In presence of which catalyst do we get nitriles from aldehydes?
a) Zn-Al
b) Cu-Al
c) Cu-Zn
d) All of the mentioned
Answer: c
Clarification: Nitriles can be obtained by the ammonolysis of aldehydes in the presence of Cu-Zn catalyst and around 300-350’C and also that cobalt or copper and zinc are specific catalysts for the preparation of nitriles by reacting aldehydes and ammonia.
4. The treatment of which of the following compound is affected in liquid phase?
a) Aldehydes
b) Aldose
c) Sugars
d) All of the mentioned
Answer: d
Clarification: The treatment of the high-boiling aldehydes, aldose sugars, or ketones is generally effected in the liquid phase.
5. Which type of Aldehyde is acrolein?
a) Saturated
b) Unsaturated
c) Aromatic
d) None of the mentioned
Answer: b.
Clarification: When unsaturated aliphatic aldehydes such as acrolein are treated, saturation as well as hydroamination occurs, and a normal primary amine is obtained.
6. Hydroammolysis of ketone are carried out in Liquid phase only.
a) True
b) False
Answer: b
Clarification: The hydroammonolysis of ketones to amines can be carried out in either the vapor or the liquid phase.
7. For highly reactive compounds, which type of reacting is preferred?
a) Hydrogenation
b) Dehydrogenation
c) Addition
d) Substitution
Answer: c
Clarification: The formation of amines by addition reactions is confined to highly reactive compounds.
8. The primary addition compounds are quit unstable.
a) True
b) False
Answer: a
Clarification: The primary addition compound is so unstable or reactive that secondary reactions occur before a stable amine is obtained.
9. By the reaction of NH3 and CO2, what product do we get ?
a) Ammonium carbamate
b) Ammonium carbonate
c) All of the mentioned
d) None of the mentioned
Answer: a
Clarification: By reaction of ammonia and carbon dioxide we get ammonium carbamate which is used to make urea.
10. What acts as a limiting factor in production of urea?
a) Hydrogen
b) Water
c) Carbon
d) Nickel
Answer: b
Clarification: The transformation of ammonium carbamate to urea is not a direct dehydration, the presence of water is, however, a limiting factor with respect to the extent that the reaction occurs.
11. What product do we get when NH3 and CS2 are reacted?
a) Thiocarbamic acids
b) Dithiocarbamic acids
c) Trithiocarbamic acids
d) None of the mentioned
Answer: b
Clarification: The addition of ammonia or alkylamines to CS2 to form the amine salts of dithiocarbamic acids.
12. Ammonia is added to cyanamide to produce what?
a) guanidine
b) Buanidine
c) Aniline
d) Amide
Answer: a
Clarification: Ammonia adds to cyanamide to form guanidine. It is presumed that addition occurs at the (-CN) group with the formation of the amidine.