Which property is not found in an ideal solution?

When two liquids $A$ and $B$ are mixed,their boiling point becomes greater than both of them. What is the nature of this solution?

Vapour pressure of pure acetone and chloroform at $328 \, K$ are $741.8 \, mm \, Hg$ and $632.8 \, mm \, Hg$ respectively. Assuming that they form an ideal solution over the entire range of composition,plot $p_{total}$,$p_{chloroform}$,and $p_{acetone}$ as a function of $x_{acetone}$. The experimental data observed for different compositions of the mixture is:

$100 \times x_{acetone}$	$0, 11.8, 23.4, 36.0, 50.8, 85.2, 64.5, 72.1$
$p_{acetone} / mm \, Hg$	$0, 54.9, 110.1, 202.4, 322.7, 405.9, 454.1, 521.1$
$p_{chloroform} / mm \, Hg$	$632.8, 548.1, 469.4, 359.7, 257.7, 193.6, 161.2, 120.7$

$A$ mixture of benzene and toluene forms

Which of the following pairs of liquids shows a negative deviation from Raoult's law?

Which one of the following is incorrect for an ideal solution?