Electrochemistry WORKSHEET vSum17 BLANK (7) (1)

Arizona State University School of Molecular Sciences 1 How Can the Identity of Metals Be Determined? This worksheet does not replace good lab notebook keeping! ALL INFORMATION RECORDED ON THIS WORKSHEET SHOULD COME FROM THE BOOK, PRELAB NOTES, THE LAB MANUAL AND PROCEDURES/VALUES/CALCULATIONS YOU HAVE RECORDED IN YOUR NOTEBOOK! 1. Part 1: In the table below, record the voltaic cell potential, E o cell , measurements for the combination of each metal with Metal 1. Include signs and units. Based on your observations, fill in whether M1 is the anode or the cathode for a (spontaneous) voltaic cell. ( Also record this data in your lab notebook .) Table 1: Building a Voltaic Cell Metal Paired With M1 E o cell with M1 as the Cathode (red lead) E o cell with M1 as the Anode (black lead) Is M1 the Anode or the Cathode? M1 0 V 0 V N/A M2 0.78 -0.78 Cathode M3 0.49 -0.49 Cathode M4 -0.39 0.39 Anode M6 1.51 -1.51 Cathode 2. Fill in Table 2 below to determine the identity of each of the unknown metals. Recall : E o cell = E o red (cathode) - E o red (anode) Table 2: Identification of Unknown Metals Metal Paired With M1 E o cell Experimental (From Table 1) E o red Experimental (Calculated from E o cell and E o red (Cu) ) Possible Identity (Use reference table to help) Actual Identity (Confirmed by TA) E o red from Reference Table M1 N/A N/A N/A 0.337 M2 0.78 -0.403 Zinc -0.763 M3 0.49 -0.153 Lead -0.126 M4 -0.39 0.727 Silver 0.799 M6 1.51 -1.173 Magnesium -2.37 Lab Section (or Day-Time) and Group Number ___W 4:00 – 5:50pm Group 5__ Due Date: _11/22/2023___ Names: Alyssa Bandin, Shabathya Williams, Daniel Rodriguez, Jeremy Hughes

Arizona State University School of Molecular Sciences 2 3. Answer the following questions about the data collected/calculated in Tables 1 and 2. a. Why must the identity of at least one of the metals be known? How were you able to determine the identity of Metal 1, and what is its reduction potential? At least one of the metals must be known when doing the equation the known metal could be the E o red (cathode), E o red (anode) in the equation given in step 2 then you would solve for the x that is not given in the equation as the experimental voltage would be E o cell . b. How do you know which value of E o cell from Table 1 is the correct cell potential value to place into the first column of Table 2? We know that the value is the correct as we determined in Table 1 if it was cathode or anode and cathode is a positive value while anode is a negative value so the positive value is for metals that are cathode and the negative values are for those that are anode. c. Show one sample calculation for the E o red experimental values placed in the second column of Table 2. Indicate which voltaic cell is being used for the calculation. (Make sure to include all of your other calculations in your lab notebook . 0.78V = 0.337 – x  0.78V – 0.337V = -x  0.403 V  -0.403V d. Were your results accurate? Describe any problems or sources of error. (Consider how close your E o red values were to the theoretical E o red values.) The results were accurate enough to determine the correct metals that were unknown as well as getting in the right area to find the unknown metals with our calculated voltages for each unknown metal. 4. Sketch a diagram that shows your voltaic cell setup. Label all important components. (Use the diagram in the introduction to help).

Arizona State University School of Molecular Sciences 4 8. Place the metals in order of decreasing electrochemical activity based on your observations from the chemical reactions. Use the actual metal name (Ex: Cu, etc.) DO NOT use the unknown numbers. A. ____Mg_(s)___ B. ____Pb (s)____ C. ____Zn (s)____ D. ___Cu (s)_____ E. ____Ag (s)__ most active least active 9. How does the behavior of the metal from 8A define it as the most active metal? The behavior of the metal 8A Mg (s) defines it as the most active metal as it reacted with all the other metals used in the experiment 10. How does the relative activity of these metals relate to their E o red values? The relative activity of these metals was going from the most negative which was the most active metal towards the least active metals that had the most positive voltage.