Final answer:
The stronger base between CH3NH2 and (CH3)2NH is (CH3)2NH due to increased electron density from the alkyl groups, which results in (CH3)2NH2+ being the stronger acid when protonated.
Step-by-step explanation:
In chemistry, especially when discussing acids and bases, the strength of a base or acid is determined by how well it donates or accepts a proton (H+). A stronger base is more likely to accept a proton, while a stronger acid is more likely to donate one.
For the given compounds CH3NH2 (methylamine) and (CH3)2NH (dimethylamine), the stronger base is (CH3)2NH. This is because the presence of more alkyl groups, such as the two methyl groups in dimethylamine, increases the electron density of nitrogen, making it more able to accept a proton.
Conversely, the conjugate acid formed by adding a proton to dimethylamine, (CH3)2NH2+, will be the stronger acid compared to CH3NH3+. This is because it has better stabilization of the positive charge due to the electron-donating effect of the methyl groups.