I believe that it can form 2 hydrogen bonds, one with oxygen and the other with hydrogen but a classmate said that oxygen can form 2 hydrogen bonds? Is this true? I can't find anything on google to support or refute that claim.
Although this was an MD study (and might be said to be somewhat dated), quoting from Matsumoto and Gubbins (Ref. 1):
Most of the molecules are in the two-bonding state, but a small fraction of molecules are in the one- or three-bonding state, as already pointed out in previous studies. 7 ,8
According to this study most of the methanol molecules form 2 H-bonds but ~4-7% form 3.
- Matsumoto, M., Gubbins, KE. The Journal of Chemical Physics 93(3):1981-1994 (doi 10.1063/1.459076).
If we consider n methanol molecules such that intermolecular H bonding exists between all( value of distance has value that allows intermolecular H bonding). One molecule has 1 O atom that bonds with n-1 H atoms. This case is for n atoms. So, number of bonds should be n(n-1). The H atom on 1molecule is counted as this bond is formed by other molecules having O.