(show all your works and please do all questions from part a to part c appear in
ID: 1015163 • Letter: #
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(show all your works and please do all questions from part a to part c appear in the picture below)
(30 pts) Electrolyte Solutions Salt solutions used as reactants or electrolytes in aqueous electrochemical cells very often employ sodium, potassium, nitrate, or suliate sales as the counter-ions for the active cation or active anion of each half-cell. (a) Explain why the sodium ion or potassium ion are not reduced in aqueous solution (b) Explain why nitrate anions will not be oxidized, but the nitrite ion could be oxidized in aqueous electrochemical cells. (c) Explain why sulfate anions will not be oxidized, but the sulfite ion could be oxidized in aqueous elec chemical cells.Explanation / Answer
A] The reason is that the reduction potential of Na+ and K+ is more than the reduction potential of water .
So in aqueous solutions ; water undergoes reduction due to its low reduction potential .
Example : (E° = –2.7 v) for Na+ ; (–1.23 v).for H2O
B] The oxididation potential of Nitrate ion is more negative compared to that of Nitrite ion .
The redox potentials values imply that oxidation of H2O to O2 is preferred over oxidation of nitrate ions in aqueous solutions.
But Nitrite ion can easily oxidize than from H2O to O2 ; so nitrite ion undergoes oxidation
So in aqueous solutions ; Nitrite ion undergoes oxidation but not Nitrate ion .
C] The oxididation potential of Sulphate is more negative compared to that of Sulfite ion .
The redox potentials values imply that oxidation of H2O to O2 is preferred over oxidation of suphate ions in aqueous solutions.
But sulfite ion can easily oxidize than from H2O to O2 so in aqueous solutions sulphite undergoes oxidation.
So in aqueous solutions ;Sulphite ion undergoes oxidation but not Sulphate ion .
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