Arrange the following amines in order of decreasing base strength. NH3, NH2Br, CH3NH2, (CH3)2NH
Look up Kb in tables and go from there. I know NH3 is 1.8 x 10^-5 and CH3NH2 is 4.8 x 10^-4, dimethylamine (CH3)2NH is 5.9 x 10^-4 but I don't have the other one in the table I have at home.
Strongest --> Weakest Base:
(CH3)2NH CH3NH2 NH3 NH2Br