In chemistry, we did a lab using zinc as the standard and forming galvanic cells with it and another solution. We determined the voltage of each cell. The next step is to form a chart of reduction potentials using zinc as the standard (v=0). How do I do this?
I would put zinc at zero, then + potentials above it in the order you found, and - below in reverse order, so that the least is at the bottom and the max is at the top.
To form a chart of reduction potentials using zinc as the standard, you'll need to collect data from the galvanic cells you've created. The voltage you determined for each cell represents the potential difference between the two half-reactions occurring at each electrode.
Here is the step-by-step process:
1. Write down the half-reactions: Write down the oxidation and reduction half-reactions that occur at each electrode. For example, if one of your cells contained zinc and copper, the half-reactions would be:
Zn(s) → Zn^2+(aq) + 2e^- (oxidation half-reaction)
Cu^2+(aq) + 2e^- → Cu(s) (reduction half-reaction)
2. Determine the overall cell potential: Subtract the reduction potential of the oxidation half-reaction from the reduction potential of the reduction half-reaction. In our example, let's say you determined the cell potential to be +0.76 volts. Note that this value should be positive since the oxidation half-reaction is written on the left side of the equation.
3. Assign a reduction potential of zero to zinc: Since zinc is your chosen standard, assign it a reduction potential of zero. This step allows you to determine the reduction potentials of other substances relative to zinc.
4. Calculate the reduction potentials: Subtract the cell potential (step 2) from the reduction potential of zinc (assigned as zero) to obtain the reduction potential for the other substance. In our example, since the cell potential was +0.76 volts, the reduction potential of copper would be +0.76 volts.
5. Repeat for other substances: Perform steps 2-4 for all the other galvanic cells you created in your lab. Assign a reduction potential of zero to zinc for each calculation.
6. Record the reduction potentials: Create a chart with two columns, one for the substances involved in the galvanic cells, and another for their corresponding reduction potentials relative to zinc. Write down the reduction potentials you calculated for each substance.
By following these steps and performing the necessary calculations, you can create a chart of reduction potentials relative to zinc as the standard.