Q46P - Chemistry: Molecular Nature Of Matter And Change

Question

Use the following half-reactions to write three spontaneous reactions, calculate ${E^{\circ }}_{cell}$ for each reaction, and rank the strengths of the oxidizing and reducing agents:

(1) ${\mathbf{\text{Al}}}^{\mathbf{\text{3 + }}}{\mathbf{\text{(aq) + 3e}}}^{\mathbf{\text{ - }}}\mathbf{\text{nAl(s)}}$${\mathit{E}}^{\mathbf{\circ }}\mathbf{=}\mathbf{-}\mathbf{1}\mathbf{.}\mathbf{66}\mathit{V}$  (2) ${\mathbf{\text{N}}}_{\mathbf{\text{2}}}{\mathbf{\text{O}}}_{\mathbf{\text{4}}}{\mathbf{\text{(g) + 2e}}}^{\mathbf{\text{ - }}}{\mathbf{\text{n2NO}}}_{\mathbf{\text{2}}}^{\mathbf{\text{ - }}}\mathbf{\text{(aq)}}$${\mathit{E}}^{\mathbf{\circ }}\mathbf{=}\mathbf{0}\mathbf{.}\mathbf{867}\mathit{V}$

(3)${\mathbf{\text{SO}}}_{\mathbf{\text{4}}}^{\mathbf{\text{2 - }}}{\mathbf{\text{(aq) + H}}}_{\mathbf{\text{2}}}{\mathbf{\text{O(l) + 2e}}}^{\mathbf{\text{ - }}}{\mathbf{\text{nSO}}}_{\mathbf{\text{3}}}^{\mathbf{\text{2 - }}}{\mathbf{\text{(aq) + 2OH}}}^{\mathbf{\text{ - }}}\mathbf{\text{(aq)}}$ ${\mathit{E}}^{\mathbf{\circ }}\mathbf{=}\mathbf{0}\mathbf{.}\mathbf{93}\mathit{V}$acidic solutions react spontaneously to the process of reduction and oxidation also used into half reaction and the electrons and atoms on both sides.                   

Step-by-Step Solution

Answer

The reaction to be spontaneous to be combined and reversed solution and the cancel common terms of oxidising agents and reducing agents

Step 1: Identify the electrochemical problem

Identify half-reactions and species.

Step 2: Write the half-reactions

Write oxidation and reduction half-reactions.

Step 3: Apply electrochemical equations

Use E_cell = E_cathode - E_anode or Nernst equation.

Step 4: State the answer

The answer is:

The reaction to be spontaneous to be combined and reversed solution and the cancel common terms of oxidising agents and reducing agents