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The Downs Cell uses a molten electrolyte containing NaCl to produce sodium at an iron cathode - VCE - SSCE Chemistry - Question 5 - 2003 - Paper 1
Question 5
The Downs Cell uses a molten electrolyte containing NaCl to produce sodium at an iron cathode. Explain why an aqueous solution of NaCl cannot be used to produce sodi... show full transcript
Worked Solution & Example Answer:The Downs Cell uses a molten electrolyte containing NaCl to produce sodium at an iron cathode - VCE - SSCE Chemistry - Question 5 - 2003 - Paper 1
Step 1
Explain why an aqueous solution of NaCl cannot be used to produce sodium at an iron cathode.
Answer
In an aqueous solution of NaCl, water is preferentially reduced at the cathode instead of sodium ions. The reduction potential for water to form hydrogen gas is more favorable than that of sodium ions, thus leading to the formation of hydrogen gas instead of sodium metal.
Step 2
Explain why alumina dissolved in molten cryolite is used in preference to molten alumina.
Answer
Using alumina dissolved in molten cryolite lowers the melting point of the electrolyte, resulting in energy savings. Cryolite acts as a solvent for alumina, preventing the need for high temperatures that molten alumina would require. This enhances the efficiency of the electrolytic production process.
Step 3
Explain why the enzyme is no longer active if its tertiary structure is disrupted.
Answer
The tertiary structure of an enzyme is crucial for its function as it determines the shape of the active site where substrate binding occurs. If this structure is disrupted, the active site is altered or destroyed, preventing substrate recognition and binding, rendering the enzyme inactive.
Step 4
Explain why the enzyme loses its tertiary structure yet its primary structure remains intact after boiling.
Answer
When the amylase enzyme is boiled, the heat disrupts the tertiary structure held together by hydrogen and van der Waals bonds. However, these high temperatures do not break the covalent bonds in the primary structure, which are peptide bonds linking the amino acids. Therefore, the primary structure remains intact despite the loss of tertiary structure.