How many convenience outlets in each room?

In every kitchen, family room, dining room, living room, parlor, library, den, bedroom, or similar room or area of dwelling units, receptacle outlets shall be installed so that no point along the floor line in any wall space there is more than six feet, from an outlet in that space. This is to prevent the use of extension cords. Outlets are usually placed about 18 inches above floor level. Switches usually go about 48 inches from floor level.  Air conditioners should be on a single dedicated circuit.