Selective Oxidation The standard reduction potential for the half-reaction Sn4+ + 2e - Sn2+ is +0.15 V. Consider data from the table of standard reduction potentials for common half-reactions, in your text. For a galvanic cell under standard conditions, which of the following cathodic half reactions would produce, at the anode, a spontaneous oxidation of Sn to Sn2+ but not Sn2+ to Sn4+. Fe2+ + 2e - Fe 2H2O + 2H2 + 20H Cu2+ + e - Cut Sn4+ + 2e Sn2+ v 2H+ + 2e H2 Sn2+ + 2e - Sn