Rank ethanol and dimethylether in terms of their normal boiling points ($T_B$):
HH
H-C-C-O-H
HH
$H_3C-O-CH_3$
a. $T_{B,ethanol} > T_{B,ether}$
b. $T_{B,ethanol} \approx T_{B,ether}$
c. $T_{B,ethanol} < T_{B,ether}$
d. can't predict without additional information
For carbon disulfide ($CS_2$) the $\Delta H_{vaporization}$ is