Question

For the electrolytic cell in a chlor-alkali plant, which of the following statements is/are correct?

• A. A membrane cell operates at a higher brine concentration than a diaphragm cell.
• B. Chlorine gas is produced at the cathode.
• C. Hydrogen gas is produced at the cathode.
• D. The caustic product stream exits the cathode compartment.

Hint:

In chlor-alkali processes, remember: chlorine is produced at the anode, hydrogen at the cathode, and sodium hydroxide exits from the cathode compartment.

Answer 1

The Correct Option is A

Step 1: Analyze the operation of chlor-alkali electrolytic cells. - In chlor-alkali electrolysis, brine (sodium chloride solution) is electrolyzed to produce chlorine, hydrogen, and sodium hydroxide. - The membrane cell operates at a higher brine concentration than the diaphragm cell to ensure better ion separation and efficiency. - Chlorine gas is produced at the anode, not the cathode. - Hydrogen gas is produced at the cathode due to the reduction of water. - The caustic product stream (sodium hydroxide) exits from the cathode compartment. Step 2: Evaluate the statements. 1. (A): Correct. Membrane cells operate at a higher brine concentration than diaphragm cells. 2. (B): Incorrect. Chlorine gas is produced at the anode, not the cathode. 3. (C): Correct. Hydrogen gas is produced at the cathode due to water reduction. 4. (D): Correct. The caustic product stream exits the cathode compartment. Step 3: Conclusion. The correct statements are: \[ \text{(1), (3), (4).} \]