Hi Abby.
Surely the water vapour will assume its own vapour pressure. The higher its vapour pressure then just the less of the other gases?
Surely the water vapour pressure is constant, regardless of the rising total pressure on account of the pressure of each additional gas?
With or without air is the water vapour dew point not the same? This is why wet air is lighter than dry air - """""WHAT"""""waters atomic mass is less?