Chemistry - Liquid Solution Question with Solution | TestHub

$\Delta \text{P}=185-183=\text{2 torr}$

${\text{M}}_{{\text{CH}}_3-\underset{\stackrel{||}{\text{O}}}{\text{C}}-{\text{CH}}_3}=15\times 2+16+12=\text{58 g/mol}$

$\frac{\Delta \text{P}}{{\text{P}}^0}=\frac{185-183}{185}=\frac{2}{185}={\text{X}}_{\text{B}}=\frac{\frac{\text{1.2}}{\text{M}}}{\left(\frac{\text{1.2}}{\text{M}}\right)+\frac{100}{58}}$

$\frac{\text{1.2}}{\text{M}}\text{<<}\frac{100}{58}$

$\Rightarrow \frac{2}{185}=\frac{\text{1.2}}{\text{M}}\times \frac{58}{100}$

$\text{M}=\frac{58\times \text{1.2}}{100}\times \frac{185}{2}$

$=\text{64.38}\approx \text{64 g/mol}$