Which of the following mixtures does not show positive deviation from Raoult's law?

Benzene and toluene form an ideal solution. If the partial vapor pressures of benzene and toluene are $1.55 \ kPa$ and $1.85 \ kPa$ respectively,what is the mole ratio of benzene to toluene in the solution?

Liquids $A$ and $B$ form an ideal solution. The vapour pressure of pure $A$ and $B$ are $50 \ mm \ Hg$ and $32 \ mm \ Hg$ respectively at $300 \ K$. One mole of liquid $A$ is mixed with $1$ mole of liquid $B$. What is the approximate mole fraction of $A$ in the vapour phase?

$A$ mixture of toluene and benzene forms a nearly ideal solution. Assume $p_{B}^{\circ}$ and $p_{T}^{\circ}$ to be the vapour pressures of pure benzene and toluene,respectively. The slope of the line obtained by plotting the total vapour pressure versus the mole fraction of benzene is $....$

What are the values of $\Delta H_{mix}$ and $\Delta V_{mix}$ for an ideal solution?

Liquids $A$ and $B$ form an ideal solution for all compositions of $A$ and $B$ at $25^{\circ} C$. Two such solutions with $0.25$ and $0.50$ mole fractions of $A$ have total vapor pressures of $0.3 \ bar$ and $0.4 \ bar$,respectively. What is the vapor pressure of pure liquid $B$ in $bar$?