Write Nernst equation for the reaction
(i) `2Cr(s)+3Cd^(+ +)(aq)to2Cr^(3+)(aq)+3Cd(s)`
(ii) `2Cr+3Fe^(+ +)to2Cr^(3+)+3Fe`

Explanation

To derive the Nernst equation for the given reactions, we will follow a systematic approach. The Nernst equation relates the cell potential (E_cell) to the standard cell potential (E°_cell) and the concentrations of the reactants and products involved in the electrochemical reaction.

### Step-by-Step Solution:

**(i) For the reaction:**
\[ 2Cr(s) + 3Cd^{2+}(aq) \rightarrow 2Cr^{3+}(aq) + 3Cd(s) \]

1. **Identify the half-reactions:**
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