PA and PB are the vapour pressure of pure liquid components, A and B, respectively of an ideal binary solution. If XA represents the mole fraction of component A, the total pressure of the solution will be.
1
PA + XA(PB − PA)
2
PB + XA(PB − PA)
3
PA + XA(PA − PB)
4
PB + XA(PA − PB)