Complete the following equation :
(i) `Cr2O_(7)^(2-)+2OH^(-)rarr`
(ii) `MnO_(4)^(-)+4H^(+)+3e^(-)rarr`

Explanation

To complete the given equations, we will analyze each part step by step.

### Part (i): Completing the equation for `Cr2O7^(2-) + 2OH^(-)`

1. **Identify the Reactants**: The reactants are dichromate ion `Cr2O7^(2-)` and hydroxide ions `OH^(-)`.

2. **Determine the Oxidation State of Chromium**: In `Cr2O7^(2-)`, let the oxidation state of Chromium be `X`. The equation for the oxidation state can be set up as:
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