1. N2O4 Catalyzed oxidation of Dimethyl sulfide in vapor phase to Dimethyl sulfoxide is an explosive reaction. Is the statement true/false?
a) True
b) False
Explanation:The statement is true, hence to avoid explosion Dimethyl sulfide in Dimethyl sulfoxide solution is oxidized in liquid phase in presence of mixture of nitrogen monoxide and oxygen. Due to presence of excess DMSO process is controlled.
2. Coal is a hydrogen rich hydrocarbon. Is the statement true/false?
a) True
b) False
Explanation:The statement is wrong as the general chemical formula of coal is (C3H4)x, which clearly states that it is a hydrogen-deficient hydrocarbon and has interlocked aromatic rings.
3. Which of the following statements regarding coal are correct?
a) Coking coals do not soften on heating
b) Non coking coals soften on heating
c) Coke is an oxidizing agent
d) Coal is a hydrogen deficient hydrocarbon
Explanation: Coking coals soften and non coking coals do not soften on heating. The product formed during heating of non coking coal is called char. Coke is a reducing agent as it is hydrogen deficient hydrocarbon.
4. The gas from the oven in Coking process of coal is scrubbed with H2S04 to remove ammonia. Is the statement true/false?
a) True
b) False
Explanation:The statement is true and the gas from the oven is cooled to remove tars, to remove aromatics it is scrubbed with light oil, scrubbed with sulfuric acid to remove ammonia leaving behind coal gas.
5. Which of the following way is used to fed hydrogenation processes in hydrogenation of coal?
a) Feeding the non powdered coal directly in presence of oxygen
b) By feeding paste of pulverized coal and heavy oil
c) Treating of non powered coal by solvent extraction
d) Feeding the non powdered coal directly along with stream of hydrogen
Explanation:Various ways used for feeding coal to hydrogenation processes are i. Treating powdered coal by solvent extraction and then feeding ii. By feeding paste of pulverized coal and heavy oil iii. Feeding powdered coal directly with stream of hydrogen.
6.Catalyst used in hydrogenation of coal is ___________________
a) Titanium oxide
b) Chromium oxide
c) Manganese oxide
d) Nickel
Explanation: 1% solution of Titanium oxide or molybdenum oxide is used as catalyst in hydrogenation of coal to impregnate the coal into reaction zone.
7. The inlet speeds of coal dust and oxygen blown into gasification chamber are _________ than the velocity of flame propagation
a) Higher
b) Lesser
c) Greater than or equal to
d) Less than or equal to
Explanation: The inlet speeds of coal dust and oxygen must be higher than velocity of flame propagation. Then at the base of chamber ash falls into water seal and hot gases escape through top of the chamber.
8. Which material of construction is used in reactor steels(hydrogenation of coal) to avoid hydrogen embrittlement?
a) Tool steel
b) Chromium-molybdenum steel
c) Stainless steel
d) Carbon steel
Explanation: Chromium-molybdenum steels are used as material of construction in reactor steels to avoid hydrogen embrittlement. Coal must be fed in powdered form into the hydrogenators reactor.
9. Which of the following unit operation is based on difference in freezing point?
a) Adsorption
b) Extraction
c) Crystallization
d) Distillation
Explanation: All are physical changes or unit operations used in petroleum refinery process. Unit operation crystallization is based on difference in freezing point difference. Wax preparation process uses crystallization method.
10. Which of the following relation between driving force and unit operation is correct?
a) Crystallization – relative solubility in different solvents
b) Extraction – relative volatilities
c) Absorption – freezing point difference
d) Adsorption – relative adherence
Explanation: The general driving force for any unit operation is concentration gradient or more precisely chemical potential. The correct option is that adsorption is based on relative adherence.