 Now that you know how to make a voltage cell what we're going to do is do four metals at one time and look at activities as well as voltage. So you have copper nitrate around the copper, you have silver nitrate around silver, zinc nitrate around the zinc and lead nitrate around the lead with a space in the middle for your salt bridge of potassium nitrate. Now what I want you to do is to record the voltage with each metal in the series and what color probe is at that metal. So here we have copper and silver, notice the silver was on the red. Now we have copper and lead and the voltage. We have a positive value with the red on copper and the black on zinc, red on silver, black on zinc, red on lead, black on zinc, red on silver and black on lead. Now what you need to do is to write half reactions for each of the reactions that you've seen here and calculate the voltage and compare that voltage to your theoretical values.