Unit Processes Multiple Choice Questions on “Technical manufacturing of amino compound – 1”.
1. Ammonia is manufactured by addition of H2 to N2 on which catalyst?
a) Cu
b) Zn
c) Fe
d) Al
Answer: c
Clarification: Most of the world’s ammonia supply is manufactured by the addition of hydrogen to nitrogen over an iron-based catalyst at elevated temperatures and pressures.
2. The reaction of H2 to N2 is highly ______. Fill in the blank.
a) Endothermic
b) Exothermic
c) Neutral
d) None of the mentioned
Answer: b
Clarification: The reaction of ‘nitrogen with hydrogen to form ammonia is a highly exothermic reaction. According to Le Chatelier.
3. What happens to equilibrium as temperature increases?
a) Increases
b) Decreases
c) Remains constant
d) None of the mentioned
Answer: b
Clarification: The amount of ammonia formed at equilibrium decreases as the temperature is increased and increases as the pressure is increased, in accordance with the Le Chatelier Braun principle.
4. What is the stoichiometric ratio of N2 to H2?
a) 1:1
b) 1:2
c) 1:3
d) 3:1
Answer: c
Clarification: To obtain maximum conversion percentages at the selected operating pressures and temperatures, the law of mass action dictates that nitrogen and hydrogen be kept at the stoichiometric ratio of 1:3 and that gases which would cause lower partial pressures of the reactants should not be present.
5. Which gas is very important for the synthetic ammonia manufacture?
a) Synthesis gas
b) Nitrogen gas
c) Hydrogen gas
d) All of the mentioned
Answer: a
Clarification: Highly purified synthesis gas is a prime requirement for synthetic ammonia manufacture, and since its nitrogen content originates from air, hydrogen is the more costly component.
6. Complete the following reaction: CH4 + H2O —-> ____ + 2H2O.
a) CO
b) CO2
c) O2
d) None of the mentioned
Answer: a
Clarification: Natural gas is the major source of hydrogen, the reaction is as follows: CH4 + H2O —-> CO + 2H2O.
7. Formation of HCN from NH3, CH4 and O2 reacts on which catalyst?
a) Zinc
b) Iron
c) Platinum
d) All of the mentioned
Answer: c
Clarification: The synthesis of HCN from ammonia, methane (natural gas), and air. The over-all reaction CH4 + NH3 + 1.5 O2—–>HCN + 3H20 can be carried out effectively at about 1000°C over platinum-alloy screen catalysts.
8. To achieve optimum yield in synthesis of HCN, oxygen should be in excess.
a) True
b) False
Answer: b
Clarification: In order to obtain optimum yields, it is necessary to use less oxygen (as air) than the amount shown in the above equation, to prevent excessive oxidation of ammonia to nitrogen oxides and methane to carbon oxides.
9. Chlorobenzene in presence of NH3 gives what?
a) Aniline
b) Benzene
c) Phenol
d) HCl
Answer: a
Clarification: C6H5-Cl + NH3—–> C6H5-NH2 + HCl.
10. Why should we increase the ratio of NH3 in the above reaction?
a) Better yield
b) Aniline production
c) Good quality
d) All of the mentioned
Answer: d
Clarification: An increase in the NH3 ratio results in: (1) a better yield of aniline, (2) an increase in the ratio of aniline to phenol, and (3) a slight diminution in the yield of diphenylamine.
11. What is the name of the following compound: C6H5-NHCH3 ?
a) Methylebenzo
b) Methyleamine
c) Methylaniline
d) Aniline
Answer: c
Clarification: The compound name is methylaniline, as methyl group -CH3 is attached to the amine group.