[cloudy1290]

Water and N2 is mixed together in a container, dissolved amount of N2 is negligible (the container is  lid by a piston).

1. Initially, total pressure (N2+water) inside container and vapour pressure of H2O are given. Find partial pressure of N2

2. Later, press down the container to reduce its volume, then find new pressure at constant T

Do I have to use Raoult's law? or it's just Total Pressure = Partial Pressure of N2 + vapour pressure of H2O

For 2nd; P(of total, before pressing)V(before pressing) = P(after pressing)V(after pressing)

are these methods correct?

[cloudy1290]

For 1, just got that Total pressure = Partial pressure of N2 + vapour pressure of H2O

But still have no idea for 2

[mjc123]

How does the pressure of nitrogen vary with the volume at constant T?
How does the vapour pressure of water vary with the volume at constant T?