I am having a problem with the first problem, the last question. I obtain a value of 101.75° for C-O-H angle in methanol, when it should be clearly between 105°(water) and 110°(diethylether), it actually is 108°.
Here's my work:
Applying a consequence of cosinus theorem:
*sqrt(1+cos105°). Hence, μO-H
=1.5158 D .
=1.12788 D .
Now, for methanol: α=(μ2methanol
Is there any mistake? Maybe they neglected C-H interactions, even if they are more or less included in experimental C-O dipole moment from diethylether.