How would you know whether a redox reaction

How would you know whether a redox reaction is taking place in an acidic, alkaline or neutral medium?

If ${{H}^{+}}$ or any acid appears on either side of the chemical equation, the reaction takes place in the acidic solution. If OH-, or any base, appears on either side of the chemical equation, the solution is basic. If neither H +, OH nor any acid or base is present in the chemical equation, the solution is neutral.