Question

1. For the given process, identify the metal oxidation states, write a balanced half-reaction in acidic
solution, and sketch a simple redox predominance diagram containing the two species. Which should
predominate at +1.0 V?
H2MoO4 → MoO2 E0 = +0.65 V

Answer 1

Consider the equation, H M00→Moo E.=0.65 V Oxidation state of H,M00, = 0 Oxidation state of Mo in H,M00, is as follows: 2+x-8=0 x=+6 Oxidation state of Mo in Moo, is as follows: y - 4=0 y=+4 In acidic solution, the half-cell reaction is as follows: M00,- +8H* +4e → Mo2+ + 4H20 Use the Nernst equation as follows: E = E.- 0.059 [product] log reactant] E=E, 7 109 M00,-] E = E. -0.059og [Mo^] 1= 0.65+0.059log [M00,?]

[Moo,-lasa == 35.6 =1035.6 =3.92 x 1035 Mo+] Hence, [M00,?]>>[Mo?] So, M002-/ H,M00, will predominate at the provided condition.