If you measure from any point on the wall above the counter top horizontally 24inches you should reach a receptacle, and not more than 18 or 20 inches high above counter top. I don't remember off hand. Same as a wall space when you measure on any point of the wall space 6' horizontally you should reach a receptacle. So above a counter top where a specific space requires a receptacle depending on dimensions you should have a recep. not farther than 48" apart. There fore you would measure 24" on any point of wall a recep.
If you have a peninsula there are dimensions that require us to,have at least one recep.