can you file back mortgage payment in a chapter 7

I'm not entirely sure I understand your question.  Are you asking if you can catch up on past due mortgage payments in a Chapter 7 case?  If so, the answer is no.     If you're asking whether the debt owed on the mortgage is discharged in a Chapter 7 case, the answer is yes (assuming you receive a discharge); however, the lien secured by the property will remain.