Question

What happens if we open the lid of glass jar containing bromine gas in vaccum

Answer 1

So if we open the jar, it will be filled and appear with a brownish-red gas as bromine liquid, Since the bromine will get evaporated with a partial pressure of 0.25 atmosphere with the enough liquid at first place.

The bromine gas at room temperature with a vapour pressure about 200 mmHg.

If the bromine gas jar is not sealed, It will eventually escape and fill the room.