Question

In a voltaic cell using copper and zinc as electrodes, which of the following is true?

• A. Copper acts as the positive electrode while zinc as negative.
• B. Zinc acts as the positive electrode while copper as negative.
• C. Zinc acts as a positive electrode when the thickness of zinc electrode is more.
• D. Copper acts as a positive electrode when the thickness of the copper electrode is more.

Answer 1

The correct option is A

Copper acts as the positive electrode while zinc as negative.

At the zinc electrode, the zinc atoms get ionized and pass into solution as ${Zn}^{++}$​ ions. This leaves the zinc rod with two electrons more, making it negative. Also, two hydrogen ions ( ${2H}^{+}$​) are discharged at the copper rod, by taking these two electrons. This makes the copper rod positive.