Which of the following is not equal to zero for an ideal solution?

$2 \ moles$ each of liquids $A$ and $B$ are dissolved to form an ideal solution. What will be the mole fraction of $B$ in the vapour phase? Given: $P_A^o = 120 \ torr, P_B^o = 80 \ torr$

In a binary ideal solution of liquids $A$ and $B$ at a constant temperature,the mole fraction of $B$ in the liquid phase is $0.4$ and in the vapor phase is $0.25$. If $P_B^o = 40 \ mm \ Hg$,then the vapor pressure of pure liquid $A$ at that temperature is .......... $mm \ Hg$.

If liquids $A$ and $B$ form an ideal solution,then which of the following is true?

Which of the following liquid pairs does not show contraction in volume on mixing?

Identify the false statement among the following.