That would be fine as long as you have a proper means to circulate the air in that amount of space and also it would have to be mounted higher than normal because cold air drops.
If you have it too low the further points of the house to the unit will barely cool.
What may also work are 2 splits located at each end of the first floor to assure you have proper coverage.
Another idea is to install a second unit and a damper if there is a split in the supply between upstairs and downstairs.
Again I have zero idea how the duct was run, I just installed a 2.5 ton unit in my home because I had a single zone that was only 3.5 tons for 2500sqft. The new unit takes care of my 2nd floor and is a complete game changer. I should also be more efficient in my energy usage now.