Write the IUPAC names of the following compounds
(i) `CH_(3)-CH_(2)-overset(O)overset(||)(C)-CH_(2)-overset(O)overset(||)(C)-CH_(3)`
(ii) `CH_(3)-overset(O)overset(||)(C)-CH_(2)-CH_(2)-CH_(2)-CH_(2)-COOH`
(iii) `CH_(3)-underset(C_(2)H_(5))underset(|)(CH)-underset(C_(2)H_(5))underset(|)(CH)-CH_(3)`

Explanation

To find the IUPAC names of the given compounds, we will follow systematic steps for each compound.

### (i) `CH3-CH2-C(=O)-CH2-C(=O)-CH3`

1. **Identify the longest carbon chain**: The longest chain contains 6 carbon atoms.
2. **Number the carbon chain**: Start numbering from the end closest to the first functional group (the carbonyl group). This gives us:
- 1: CH3
- 2: CH2
...