State Raoult's law. Using the law how would you distinguish between an ideal solution and non-ideal solution ?

Explanation

Raoult.s law states that the partial vapour pressure of a volatile component of a solution is directly proportional to the mole fraction of that component at a given temperature.
For example, for a volatile component A,
`p_(A)propx_(A),p_(A)=kx_(A)` ...(i)
If `x_(A)=1` i.e. solution has only one component, then `p_(A)=kxx1`
`thereforep_(A)^(@)` = vapour pressure of a component in pure form.
So, equation (i) becomes, `p_(A)=p_(A)^(@)x_(A)`
Ideal solution : Ideal solution obeys Raoult.s law at all the concentrations and temperature.
`p_(A)=p_(A)^(@)x_(A)`
Non-ideal solution : Non-ideal solution does not obey Raoult.s law. `p_(A)nep_(A)^(@)x_(A)`