Engineering Questions with Answers - Multiple Choice Questions
Chemical Industry MCQ’s – Inorganic Chemical – Chlorine and Naoh
1 - Question
What are the co-products in the electrolysis of brine?
a) Chlorine and caustic soda
b) Soda ash and caustic soda
c) Soda ash and chlorine
d) Chlorine, caustic soda, and soda ash
View Answer
Explanation: Co-products produced in the electrolysis of brine are chlorine Cl2 and caustic soda NaOH. 80% of NaOH and >95% of Cl2 are produced in India by this process.
2 - Question
Sodium hydroxide is insoluble in water.
a) True
b) False
View Answer
Explanation: The statement is false since sodium hydroxide is highly soluble in water with high heat of solution (exothermic). It is insoluble in ether and other non-polar solvents.
3 - Question
High concentration of NaOH is produced by _____________
a) Mebrane cell process
b) Diaphragm cell process
c) Mercury cell process
d) Chemical process
View Answer
Explanation: 10-12% NaOH is produced by diaphragm cell which is concentrated to 50%NaOH. 30-33% NaOH is produced by membrane process concentrated to 50% NaOH. 70% NaOH is produced in mercury cell process.
4 - Question
Cathode used in electrolysis of brine by diaphragm cell type is _____________
a) Lead
b) Iron
c) Titanium
d) Carbon
View Answer
Explanation: Iron is used as cathode in electrolysis of brine by diaphragm cell type where H2 gas and aqueous NaOH are obtained. Anode used is graphite where chlorine is obtained.
5 - Question
Which of the following is denuding reaction?
a) NaCl+H2O →NaOH+12H2+12Cl2
b) Cl– →12 Cl2 + e–
c) Na + Hg →NaHg
d) NaHg+H2O →NaOH+12 H2 + Hg
View Answer
Explanation: Denuding reaction is the reaction of sodium amalgam with water, which on reacting produces sodium hydroxide, hydrogen, and mercury.
6 - Question
Major production of caustic soda is through ________________
a) Mercury cell process
b) Diaphragm cell process
c) Chemical process
d) Mebrane cell process
View Answer
Explanation: 88% of total production is by mercury cell process, 7% by diaphragm cell process, 4% by membrane process, and 1% through chemical process.
7 - Question
Reagent used for drying of Cl2 is ______________
a) H3PO4
b) H2SO4
c) HCl
d) HNO3
View Answer
Explanation: Minor quantities of NaOH and Na2CO3 are used for salt purification and sulfuric acid H2SO4 being dehydrating agent is used for drying of Cl2.
8 - Question
Concentration of NaOH produced in mercury cell process is ___________
a) 10-12%
b) 30-33%
c) 50%
d) 70%
View Answer
Explanation: 10-12% NaOH is produced in diaphragm cell. 30-33% NaOH is produced by membrane process. 70% NaOH is produced in mercury cell process.
9 - Question
Which of the following is an advantage of mercury cell process?
a) Pure sodium hydroxide
b) Pure chlorine gas
c) Utilization of less pure brine
d) Low electrical energy consumption
View Answer
Explanation: Advantages of mercury cell process are pure chlorine gas and pure 50% sodium hydroxide without evaporation. Pure sodium hydroxide is an advantage of membrane process. Utilization of less pure brine is an advantage of diaphragm cell process.
10 - Question
Which of the following is a disadvantage of membrane cell process?
a) Asbestos emission
b) Mercury contamination
c) High purity of brine
d) High electrical energy consumption
View Answer
Explanation: Asbestos emission is a disadvantage of diaphragm cell process. Mercury contamination and High electrical energy consumption are disadvantages of mercury process. High purity of brine is a disadvantage of membrane cell process.
11 - Question
Pure sodium hydroxide is obtained in mercury cell process. Is the statement true/false?
a) True
b) False
View Answer
Explanation: The statement is false since pure chlorine gas and pure 50% sodium hydroxide without evaporation are obtained in mercury cell process whereas pure sodium hydroxide is obtained in membrane process.
12 - Question
Diaphragm used in diaphragm cell process is ______________
a) Asbestos
b) Poly vinyl chloride
c) Wooden material
d) Woven fabric
View Answer
Explanation: Diaphragm cell is an electrolytic cell in which the anodic and cathodic liquors and products are separated by diaphragm made of asbestos.
13 - Question
Which of the following product is obtained at cathode in mercury cell process?
a) NaOH
b) NaHg
c) Cl2
d) NaCl
View Answer
Explanation: NaCl is the electrolyte used, NaOH is the product obtained in denuding tower, Cl2 is product obtained at anode, and NaHg is the product obtained at cathode in mercury cell process.
14 - Question
Membrane used in membrane cell process is ______________
a) Asbestos
b) Anion- exchange membrane
c) Cation-exchange membrane
d) Woven fabric
View Answer
Explanation: Membrane cell process uses Cation-exchange membrane since it separates anolyte and catholyte, and also prevents migration of chloride ions into catholyte.
15 - Question
Which of the following is not a requirement for membrane separators?
a) Good mechanical properties
b) Long term stability
c) High electrical resistance
d) Durability under required conditions
View Answer
Explanation: Membrane separators should have Long term stability and good mechanical properties for practical use. They must also have low electrical resistance, durability under required conditions.