Chemical Technology Multiple Choice Questions on “Synthetic Organic Chemical Industries – C1 Compounds”.
1. Which among the following methods is used for the manufacture of industrial methanol?
a) Contact process
b) Kraft’s process
c) From synthesis gas
d) From blue gas
Clarification: Methanol is manufactured from synthesis gas when it is subjected to high pressure and temperature, it converts to methanol. Sulfuric acid is manufactured by contact process. Paper pulp is manufactured by Kraft’s process.
2. What are the components of synthesis gas?
a) Mixture of H2+CO2+CO+N2
b) Mixture of CH4+H2+CO
c) Mixture of CO+H2
d) Mixture of H2+O2
Clarification: Synthesis gas is a mainly a mixture of Mixture of CO+H2. The name comes from its use as an intermediate in creating SNG (Synthetic natural gas). Mixture of H2+CO2+CO+N2 is called as producer gas. Mixture of CH4+H2+CO is called as coal gas.
3. Which among the following is the major engineering problem faced during the manufacture of methanol?
a) High pressure
b) Low pressure
c) High temperature
d) Low temperature
Clarification: Designing a high-pressure reactor is the most difficult part in manufacturing methanol. To withstand high pressure thick reactor walls are necessary.
4. What is the use of KMnO4 in the manufacture of methanol?
a) To increase pH
b) To decrease pH
c) To remove impurities
d) To increase turbidity
Clarification: KMnO4 is added to remove trace of impurities such as ketones and aldehydes. Presence of impurities decreases the purity of methanol.
5. Why is Monoethanol amine used in the manufacture of CO2 gas?
c) To increase the pH
d) To decrease the pH
Clarification: Monoethanol amine is used as a absorber for manufacture of CO2 gas because it’s a weak base which can be used as a scrubber.
6. What is the ideal pressure needed for the manufacture of liquid CO2?
Clarification: Liquid CO2 can be manufactured only if the pressure is above 5.1 atm since triple point of CO2 exists only at pressure of 5.1atm. Triple phase of a substance is temperature and pressure at which all three phases of the substance coexist.
7. Carbon dioxide can be recovered by girbotol amine process.
Clarification: Girbotol is a reversible process which uses aqueous solution of mono or di or tri ethanolamine which acts as an absorption medium and hence used to recover carbon dioxide.
8. Which among the following methods is used for the manufacture of carbon dioxide?
a) From synthesis gas
b) Lime kiln process
c) Monte Catini process
d) Kraft’s process
Clarification: In lime kiln process calcium carbonate is used along with girbotol recovery. Methanol is manufactured from synthesis gas. Kraft’s process is for the manufacture of paper pulp. Ammonium carbonate is manufactured by monte catini process.
9. What is the pressure requirement in the manufacture of methanol from synthesis gas?
a) 1-3 atm
b) 100-150 atm
Clarification: High pressure is required for the manufacture of methanol. Conversion cannot take place at low pressure as it leads to formation of intermediate compounds.