## Chemistry and Chemical Reactivity (9th Edition)

$C_7H_6N_2$
Raoult's Law: $\Delta P=-\chi P^0\rightarrow \chi=-(94.16-95.26)/95.26=0.0115$ Number of moles of benzene: $10.0\ g\div78.11\ g/mol=0.128\ mol$ Number of moles of solute: $0.0115=n/(n+0.128)\rightarrow n=0.0015\ mol$ Molar mass: $0.177\ g\div 0.0015\ mol=118.84\ g/mol$ In 1 mol of the component: $n_C\times12.01/118.84=71.17/100\rightarrow n_C=7.04\approx7$ $n_H\times1.01/118.84=5.12/100\rightarrow n_C=6.02\approx6$ $n_N\times14.01/118.84=23.17/100\rightarrow n_C=1.96\approx2$ Molecular formula: $C_7H_6N_2$