The SRD says otherwise (my emphasis):Artoomis said:Some benefits from being a melee weapon:
1. Coup de Grace at with 15' reach.....
A whip is neither a bow nor crossbow, nor would you be adjacent when 15ft away.As a full-round action, you can use a melee weapon to deliver a coup de grace to a helpless opponent. You can also use a bow or crossbow, provided you are adjacent to the target.