Experiment 11-Redox Reactions: Discover how batteries work!

Lead, with the element symbol Pb, is commonly used in batteries. Pb may appear in batteries as PbO2, Pb, PbO. What is the correct oxidation number of Pb in each of these compounds?

+4,0,+2

Based on the periodic table, what is the oxidation number of oxygen (Group VI, period 2)

-2

Where do the H+ come from at this step of balancing redox reactions in acidic environments?

Acidic solutions contain H+

In a galvanic cell, a full redox reaction takes place, one half-reaction at each electrode. How is the cell potential calculated?

By subtracting the anode potential from the cathode potential

Positive voltage means that the reaction occurs spontaneously and that energy is produced! What do you think happens with this energy here in our experiment?

It is turned into heat, the beaker will feel warm

How does a salt bridge keep the reaction going?

It transfers both cations and anions between the cells to balance the charges

In a redox reaction, what is oxidation?

The loss of electrons

Before you go, which type of molecule would you choose to be the anode in a lithium battery?

The metal with the most positive potential

How can you find the oxidation number of an ion?

The oxidation state of an ion is equal to the charge of the ion

What happens to the electrons in an oxidation reaction?

They are gained by the oxidizing agent in the other half-reaction