Determine the total voltage produced by Manganese(II) bromide and potassium metal

Question

Show ALL work. Use redox reaction to derive

Answer 1

Mg²⁺ + 2e- ==> Mg(s) ... reduction half reaction Eº_red = -2.38 V

2K(s) ==> 2K⁺ + 2e- ... oxidation half reaction x 2 to equalize electrons Eº_red = -2.92 V

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Mg²⁺ + 2K(s) ==> Mg(s) + 2K⁺ ... overal redox

Eºcell = -2.38 - (-2.92) = 0.54 V