[PieterM]

There is a wreck of a sunken submarine lying 9.2m below the surface of a freshwater lake.You need to displace 5160 cubic centimeters of water out of the balast tank in order to render the sub weightless. On the day of salvage the air temperature is 22 degrees Celsius and the water 5 degrees less. This is fresh water so consider density to be 1000. Atmospheric pressure is 101.3kPa.
I need to calculate the volume of atmospheric air that will have to be pumped into the balast tank (air in tank will be at water temperature) to displace an amount of water so as to make the submarine weightless in the water. The volume of the tube is negligible. Answer in cubic cm

Gas laws were never my favourite