What is the bond angle of the C-N-H bond angle in (CH3)2NH?
This compound is drawn like so, with the
This is called dimethylamine; amine, because of the
(You might also call this N,N-dimethylamine to emphasize the locations of the methyl groups.)
We can see the lone pair of electrons on the nitrogen, which immediately means that one of the
(This compound is NOT trigonal planar, by the way.)
You can see that it has four electron groups: two methyls, one hydrogen, and one lone pair. That corresponds to a tetrahedral electron geometry, and thus a trigonal pyramidal molecular geometry.
As a result, we can expect the bond angle to be close to
However, due to the lone pair of electrons, which take up quite a bit of space when they aren't bonding, the molecule "crunches" up a little bit, and the angle becomes LESS than
Looking up the actual bond angle, it is about
Simply enter the molecular formula, then choose the three atoms you want for your bond angle (four if it is a dihedral/torsion angle).