Comparisons of Physical Properties of Alcohols and Ethers
المؤلف:
..................
المصدر:
LibreTexts Project
الجزء والصفحة:
.................
22-10-2019
1237
Comparisons of Physical Properties of Alcohols and Ethers
Ether molecules have no hydrogen atom on the oxygen atom (that is, no OH group). Therefore there is no intermolecular hydrogen bonding between ether molecules, and ethers therefore have quite low boiling points for a given molar mass. Indeed, ethers have boiling points about the same as those of alkanes of comparable molar mass and much lower than those of the corresponding alcohols (Table 1.1).
Table 1.1 Comparison of Boiling Points of Alkanes, Alcohols, and Ethers
| Condensed Structural Formula |
Name |
Molar Mass |
Boiling Point (°C) |
Intermolecular Hydrogen Bonding in Pure Liquid? |
| CH3CH2CH3 |
propane |
44 |
–42 |
no |
| CH3OCH3 |
dimethyl ether |
46 |
–25 |
no |
| CH3CH2OH |
ethyl alcohol |
46 |
78 |
yes |
| CH3CH2CH2CH2CH3 |
pentane |
72 |
36 |
no |
| CH3CH2OCH2CH3 |
diethyl ether |
74 |
35 |
no |
| CH3CH2CH2CH2OH |
butyl alcohol |
74 |
117 |
yes |
Ether molecules do have an oxygen atom, however, and engage in hydrogen bonding with water molecules. Consequently, an ether has about the same solubility in water as the alcohol that is isomeric with it. For example, dimethyl ether and ethanol (both having the molecular formula C2H6O) are completely soluble in water, whereas diethyl ether and 1-butanol (both C4H10O) are barely soluble in water (8 g/100 mL of water).
الاكثر قراءة في مواضيع عامة في الكيمياء العضوية
اخر الاخبار
اخبار العتبة العباسية المقدسة
