Boiling Points Similar to alkanes of comparable molecular weight. TABLE 14-I Comparison of the Boiling Points of Ethers,Alkanes,and Alcohols of Similar Molecular Weights Compound Forula MW bp°C) Dipole Moment (D) water HO 18 100 1.9 ethanol CHCH2一OH 46 78 1.7 dimethyl ether CH3—OCH 46 -25 1.3 propane CHCH2CH 44 -42 0.1 n-butanol CH,CH2CHCH2一OH 74 118 1.7 tetrahydrofuran 72 66 1.6 diethyl ether CHCH2O一CHCH 74 35 1.2 pentane CH CHCHCHCH 72 36 0.1 Note:The alcohols are hydrogen bonded,giving them much higher boiling points.The ethers have boil- ing points that are closer to those of alkanes with similar molecular weights. Chapter 14 4Chapter 14 4 Boiling Points Similar to alkanes of comparable molecular weight