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General Chemistry

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Moderate

Concept: Electrolysis of Water

CHEM-ZTUVRX

The process of water electrolysis can be written in the form of two half-reactions as follows:

$$2{H}_{2}O \xrightarrow [ ]{ } {O}_{2} + 4{H}^{+} + 4{e}^{-} \quad\quad -E° = -1.23\ V$$
$$4{H}_{2}O + 4{e}^{-} \xrightarrow [ ]{ } 2{H}_{2} + 4O{H}^{-} \quad\quad E° = -0.83\ V$$

If platinum electrodes are connected to a 6-Volt battery and are dipped into pure water, no evolution of hydrogen and oxygen bubbles is observed.

Which of the following statements support this observation? Select ALL that apply.

A

Auto-ionization of pure water is limited, resulting in a large overpotential for electrolysis.

B

The battery assists in driving the anode and cathode reactions in the opposite direction.

C

Pure water contains very few ions, which allows only a negligible current to flow.

D

None of the above statements support this observation.