Whitish tissue over the blood clot of wisdom tooth extraction. as well as bad breath, had extraction 48 hours ago. is this dry socket?

Possible: food debris. Possible normal fibrin clot without trapped blood cells. Dry socket or alveolar osteitis is the result of early breakdown and loss of the clot. The pain is as a severe toothache where there is no longer a tooth. Bad taste is normal as well as halitosis.

Dry socket: A dry socket usually presents as severe pain about three days after extraction following only mild to moderate pain previously. So based merely on your description we can't know whether or not you have or will have a dry socket. Either wait it out another day or so and see what happens or better yet call your dentist and suggest having him or her see you to evaluate it.

Could be: Especially if accompanied by severe pain and fever. If you are in distress, call the Dentist or Oral Surgeon who did your surgery. He/she is responsible for your post-surgical care.