Standard Reduction Potentials Some substances are more easily reduced that others. Some substances are more easily oxidized than others. Is there a measurement that can help us compare the ease of reduction or oxidation? Yes, the standard reduction potentials (SRP), E is a table that does just that. Medell Three notable standard reduction potentials (V-volts) End Li (aq) + e→ La 2 H(aq) + 2e F: -3.05 V lowest HW 0.00 V +2⇒2(g) 2.87 V highest 1. Define reduction. 2. Give two ways you tell these are reduction reactions? 3. Write the net ionic equation for the reaction between magnesium and hydrochloric acid. 4. Write the two half reactions for the reaction between magnesium and hydrochloric acid. Oxidation: Reduction: 5. The table in Model 1 shows that the E'red for the reaction 2 H(aq) + 2e →H, is 0.00 V. Based on previous observations in the "Metol Reactivities" lab (Unit 5), does H'fog) have no (0.00) tendency to be reduced? Explain your reasoning. 6. Which family on the periodic table wants to gain electrons more than the rest? Explain your reasoning. 7. Which family on the periodic table wants to lose electrons more than the rest? Explain your reasoning. Understanding the Standard Reduction Potential Chart Teacher check The standard reduction potential is the tendency for a chemical species to be reduced, and is measured in volts at standard conditions. The more positive the potential is the more likely it will be reduced. The standard potentials are all measured at standard conditions, which in electrochemistry are 298 K, 1 atm, and with 1 M solutions. Oxidation and reduction occur together. We cannot measure a reduction potential alone so a reference point is needed. That reference point is the standard hydrogen electrode (SHE). The reaction: 2 H'(aq) + 2e-Halg) has been assigned a value of 0.00 V and all other species are compared to H'(aq) in their tendency to be reduced. when we see the reaction: Fa(g) + 2e-2 F(aq) has a reduction potential of 2.87 V, we can say that Flal is much more likely to be reduced than H'log). When we see the reaction: Li'(aq) + e Lifs) with a reduction potential of -3.05 V, we can say that Li is much less likely to be reduced than H(og)/n8. Looking at the Echart, circle the species that is more likely to be reduced. Explain your reasoning with a's as evidence. a) Cu"fog) or Ag'log) 9. Define oxidizing agent. b) Cl(g) or Bri/) 10. Circle the species that is a better oxidizing agent? Explain your reasoning (s) a) Cu" (aq) or Ag' (og) b) MnO (eg) or Cr,O, (aq) 11. On your standard reduction potential table, highlight the top ten oxidizing agents (not the whole equation). Teacher check

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