Question

Given below are two statements:
Statement I : During Electrolytic refining, the pure metal is made to act as anode and its impure metallic form is used as cathode
Statement II : During the Hall-Heroult electrolysis process, purified $Al _2 O _3$ is mixed with $Na _3 AlF _6$ to lower the melting point of the mixture
In the light of the above statements, choose the most appropriate answer from the options given below:

• A. Both Statement I and Statement II are correct
• B. Both Statement I and Statement II are incorrect
• C. Statement I is correct but Statement II is incorrect
• D. Statement I is incorrect but Statement II is correct

Answer 1

The Correct Option is D

To address the given question, we need to evaluate each statement in isolation.

Statement I: During Electrolytic refining, the pure metal is made to act as an anode and its impure metallic form is used as cathode.

Analysis: In electrolytic refining, the impure metal is actually made to act as the anode, and the cathode is a strip of pure metal. The process involves the transfer of metal from the anode to the cathode, where the pure metal is deposited over time. This incorrect representation in Statement I makes it inaccurate.

Statement II: During the Hall-Héroult electrolysis process, purified Al_2 O_3 is mixed with Na_3 AlF_6 to lower the melting point of the mixture.

Analysis: This is a correct description of the Hall-Héroult process. Purified alumina (Al_2 O_3) is dissolved in molten cryolite (Na_3 AlF_6), which indeed helps in lowering the melting point to around 950-1000°C, making the electrolysis process feasible and energy-efficient. Statement II is accurate.

Conclusion: Considering the analyses above, Statement I is incorrect because it misrepresents the roles of anode and cathode in electrolytic refining. On the other hand, Statement II accurately describes a component of the Hall-Héroult process. Therefore, the correct option is: "Statement I is incorrect but Statement II is correct."