Oxygen released into space?

1 Would there be a force behind it? Yes. The gas would leave the tank at speed, and would have mass, if not much. the gas therefore carries away momentum, and since momentum is conserved, something else must happen as well. That 'something' is the tank setting off in the opposite direction. This is exactly what happens when you let a balloon go on earth. It is also exactly what happens when the valve fails on a compressed gas cylinder. Those things, which are pressurised to much more than 1 bar, can be lethal under those circumstances.

2 Would the gas just dissipate? Yes. Although the gas jet would have a preferred direction, the individual molecules in the jet also have thermal motion. that would cause the jet to spread out and dissipate, and there is nothing in space to stop them.

3 Could you fill an isolated area in space with a gas? No. First of all, an area has only 2 dimensions, so you can't get a gas into an area. Suppose we rephrase the question and tak about an isolated volume instead. Now the question is really pretty meaningless. What do you mean by a volume being 'filled' wth a gas? Here on earth, we could imagine something (a room, a tank, whatever) being 'full' of air when the air pressure inside was standard atmospheric pressure. But in the near-vacuum of deep space, there is no equivalent. Is a volume of 1 cu.m. 'full' when it contains 1 molecule? 10? 10m? This is unanswerable, because meaningless. All you can be sure of is that the gas would disperse from the volume in question unless it had sides, in which case it wouldn't be 'space'.

What do you mean 'released into area' released by who? In any adventure, if a quantity of oxygen became by some ability placed right into a quantity of empty area, it is going to deplete straight away. in truth, area isn't a ideal vacuum, it incorporates a very tiny percentage of hydrogen atoms, yet they're so finely dispersed that it is nevertheless a more beneficial robust vacuum than lets make in the international.

If you have an unpressurized container and fill it at sealevel, and bring it then into space, you have a pressure of 1 bar inside it. Open it, and the oxygen will burst out just like if you had a 2 bar container at sea level. It would fly off, and not even very slowly.

space is a vacuum, and there is little to no gravity(unless u count what the sun provides) so the contents would flow out into space propelling forever, or until it hit soemthing.

"propel itself through the air"

What air are you referring to, there is none in space.