Name the reagent used in the following reactions:
`C_(6)H_(6)-CH_(2)-CH_(3) overset(?)to C_(6)H_(5)-COO^(-)K^(+)`

Explanation

To determine the reagent used in the reaction from ethylbenzene (C6H5-CH2-CH3) to benzoate ion (C6H5-COO^(-)K^(+)), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reaction Type**:
The reaction involves the oxidation of ethylbenzene. Ethylbenzene has a side chain (the ethyl group) that is being oxidized to form a carboxylate ion.

2. **Determine the Oxidation Process**:
...