250+ TOP MCQs on Inorganic Chemical – Chlorine and Naoh and Answers

Chemical Industry Quiz on “Inorganic Chemical – Chlorine and Naoh”.

1. 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

Answer: a
Clarification: 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. Sodium hydroxide is insoluble in water.
a) True
b) False

Answer: b
Clarification: 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. High concentration of NaOH is produced by _____________
a) Mebrane cell process
b) Diaphragm cell process
c) Mercury cell process
d) Chemical process

Answer: c
Clarification: 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. Cathode used in electrolysis of brine by diaphragm cell type is _____________
a) Lead
b) Iron
c) Titanium
d) Carbon

Answer: b
Clarification: 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. Which of the following is denuding reaction?
a) NaCl+H₂O →(NaOH+frac{1}{2} H_2+frac{1}{2} Cl_2 )
b) Cl^– →(frac{1}{2}) Cl₂ + e^–
c) Na + Hg →NaHg
d) NaHg+H₂O →NaOH+(frac{1}{2}) H₂ + Hg

Answer: d
Clarification: Denuding reaction is the reaction of sodium amalgam with water, which on reacting produces sodium hydroxide, hydrogen, and mercury.

6. Major production of caustic soda is through ________________
a) Mercury cell process
b) Diaphragm cell process
c) Chemical process
d) Mebrane cell process

Answer: a
Clarification: 88% of total production is by mercury cell process, 7% by diaphragm cell process, 4% by membrane process, and 1% through chemical process.

7. Reagent used for drying of Cl₂ is ______________
a) H₃PO₄
b) H₂SO₄
c) HCl
d) HNO₃

Answer: b
Clarification: 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. Concentration of NaOH produced in mercury cell process is ___________
a) 10-12%
b) 30-33%
c) 50%
d) 70%

Answer: d
Clarification: 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. 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

Answer: b
Clarification: 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. 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

Answer: c
Clarification: 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. Pure sodium hydroxide is obtained in mercury cell process. Is the statement true/false?
a) True
b) False

Answer: b
Clarification: 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. Diaphragm used in diaphragm cell process is ______________
a) Asbestos
b) Poly vinyl chloride
c) Wooden material
d) Woven fabric

Answer: a
Clarification: Diaphragm cell is an electrolytic cell in which the anodic and cathodic liquors and products are separated by diaphragm made of asbestos.

13. Which of the following product is obtained at cathode in mercury cell process?
a) NaOH
b) NaHg
c) Cl₂
d) NaCl

Answer: b
Clarification: 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. Membrane used in membrane cell process is ______________
a) Asbestos
b) Anion- exchange membrane
c) Cation-exchange membrane
d) Woven fabric

Answer: c
Clarification: Membrane cell process uses Cation-exchange membrane since it separates anolyte and catholyte, and also prevents migration of chloride ions into catholyte.

15. 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

Answer: c
Clarification: 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.