what is the oxidation number of (i) C in `CH_(2)O` (i) Pt in `[Pt (C_(2)H_(4))CI_(3)]^(-)`

Explanation

To determine the oxidation numbers of carbon in CH₂O and platinum in [Pt(C₂H₄)Cl₃]⁻, we will follow a systematic approach.

### Step 1: Determine the oxidation number of carbon in CH₂O

1. **Assign variables**: Let the oxidation number of carbon (C) be \( x \).
2. **Assign known oxidation states**:
- Hydrogen (H) has an oxidation state of +1. Since there are 2 hydrogen atoms, their total contribution is \( 2 \times (+1) = +2 \).
- Oxygen (O) has an oxidation state of -2. There is 1 oxygen atom, so its contribution is -2.
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