The correct answer is option 4. i-d, ii-c, iii-a, iv-b
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Column I
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Column II
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(i) Lead storage battery
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(d) Pb is anode, PbO2 is cathode
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(ii) Mercury cell
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(c) Gives steady potential
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(iii) Fuel cell
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(a) maximum efficiency
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(iv) Rusting
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(b) prevented by galvanization
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(i) Lead storage battery: In a lead storage battery, lead (Pb) serves as the anode, and lead dioxide (PbO2) serves as the cathode during discharge. This allows the battery to store and release electrical energy through the conversion of lead and lead dioxide between their respective ionic forms.
(ii) Mercury cell: A mercury cell provides a steady potential due to the use of mercury and a metal-mercurous oxide amalgam (e.g., mercuric oxide) as the cathode. The reaction at the cathode releases mercury ions, and the mercury ions combine with the amalgam, leading to a continuous supply of mercury.
(iii) Fuel cell: A fuel cell is known for its maximum efficiency in converting chemical energy (from a fuel) directly into electrical energy without combustion. The chemical reaction between the fuel (e.g., hydrogen) and the oxidant (e.g., oxygen) at the anode and cathode generates electricity.
(iv) Rusting: Rusting is the process of corrosion that occurs on iron or steel surfaces when they are exposed to moisture and oxygen. It can be prevented by galvanization, which involves coating the iron or steel with a layer of zinc. Zinc acts as a sacrificial anode and protects the underlying metal from corrosion. |
