Bubbles will form on wires attached to a 9-volt 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

I and II are correct because in electrolysis, the electrode connected to the negative terminal of the battery becomes the cathode and reduction occurs there, producing hydrogen gas from water. The electrode connected to the positive terminal becomes the anode, where oxidation occurs, producing oxygen gas from water.

Bubbles Will Form on Wires Attached to a 9-Volt Battery