Bubbles will form on wires attached to a 9 V battery placed in water. Which statements correctly describe what is happening?
(I) The wire attached to the (-) battery electrode becomes the cathode, and water is being reduced there to produce hydrogen gas.
(II) The wire attached to the (+) battery electrode becomes the anode, and water is being oxidized there to produce oxygen gas.
(III) The wire attached to the (-) battery electrode becomes the cathode, and water is being oxidized there to produce oxygen gas.
(IV) The wire attached to the (+) battery electrode becomes the anode, and water is being reduced there to produce hydrogen gas.

Question

Quizplus · Accepted Answer

Bubbles form on both wires because electrolysis of water is occurring due to the electric current produced by the battery. At the wire attached to the (-) battery electrode, water is being reduced (gaining electrons) to produce hydrogen gas, so this wire is the cathode. At the wire attached to the (+) battery electrode, water is being oxidized (losing electrons) to produce oxygen gas, so this wire is the anode. Therefore, statements I and II are correct. Statements III and IV are incorrect.

Bubbles Will Form on Wires Attached to a 9 V