[rooham1426]

need some help with chem homework if anyone could tutor me online tonight or just help me out id greatly appreciate it. you can catch me on yahoo rooham1426
Here's one question, well two?\

Would water have a higher or lower boiling point if it was linear instead of bent? What about its vapor pressure? Why

Ethanol, ch3ch2oh has a higher boiling point than dimethyl ether, ch3och3, why?

[Arkcon]

need some help with chem homework if anyone could tutor me online tonight or just help me out id greatly appreciate it. you can catch me on yahoo rooham1426
Here's one question, well two?\

Well, we can try to talk you through your specific problems one message at a time, and see if you can't crack these concepts yourself.

Would water have a higher or lower boiling point if it was linear instead of bent? What about its vapor pressure? Why

Why is a water molecule bent, and not linear?  What effect on a molecule's polarity does being "bent" or linear have?  Do you know examples of a linear molecule?

Ethanol, ch3ch2oh has a higher boiling point than dimethyl ether, ch3och3, why?

Does drawing out the structures help you?

[shelanachium]

Both C-O and O-H bonds are polar. In an O-H bond, as in water or ethanol, the positive charge is on the very small H atom. Consequently this is strongly attracted to the negative charge on the O atoms of adjacent molecules, so molecules containing O-H bonds are strongly attracted to each other and their boiling-points are relatively high - as in ethanol C2H5OH.

Dimethyl ether CH3OCH3 contains polar C-O bonds. But here the positive charge resides in the CH3 groups, which are much larger than an H atom. So the positive charge in the CH3 groups is less concentrated, and the mutual attraction of the molecules much less. So dimethyl ether boils much lower than the isomeric ethanol.

Look up HYDROGEN BONDS for further information.