Basicity of simple molecular bases
decreasing basicity  | |||
| NH3 | H2O | HF |  |
| weak base | H2S | HCl | |
| HBr | |||
| HI | |||
Any EHn compound with nonbonding pair(s) at E is capable of acting as a base.
| :NH3 |  |  |  (X = Cl, Br or I) |
The other EHn compound considered earlier, CH4 (methane), cannot act as a base because it does not have any nonbonding electron pairs at carbon.
For the same series of compounds, the trends in acidity and basicity are opposite.
The basicity of HnE is lower for E farther across a row and down a group of the periodic table.
The only HnX that is more basic than water is the weak base NH3.
Amines, which are organic compounds such as CH3NH2 or (CH3)2NH in which one or more H on NH3 has been substituted by a hydrocarbon group, are also bases.
Amines, which are organic compounds such as CH3NH2 or (CH3)2NH in which one or more H on NH3 has been substituted by a hydrocarbon group, are also bases.