the answer is going to be dependent on how much you have depreciated the condo on your taxes over time.
more likely, you have a loss, not a gain so it could save you taxes... but without additional numbers it's hard to pin it down.
the mortgage has nothing to do with the calculation...
the profit / loss is based on a) what you paid for the property (add in the closing costs from the purchase), b) what you sold the property for (less the costing costs from the sale) and adjusted for the depreciation since the beginning.
I am sure others with respond with more specifics.
