Electrolysis of dil H2SO4 liberates gases at anode and cathode:
Correct answer: C. O2 & H2 respectively
- A. O2 & SO2 respectively
- B. SO2 & O2 respectively
- C. O2 & H2 respectively
- D. H2 & O2 respectively
Explanation
In the electrolysis of dilute sulfuric acid (H2SO4), water is decomposed into oxygen and hydrogen gases. At the cathode, hydrogen ions (H+) gain electrons (reduction) to form hydrogen gas (H2):2H+ + 2e- → H2At the anode, water molecules are oxidized to produce oxygen gas (O2):2H2O → O2 + 4H+ + 4e-Thus, oxygen is liberated at the anode and hydrogen is liberated at the cathode. Options A and B are incorrect as they suggest SO2 is produced, which does not occur in this reaction. Option D incorrectly reverses the roles of the gases at the electrodes.
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