Is Methylamine (CH₃NH₂) a Strong or Weak Base?

Is Methylamine (CH₃NH₂) a strong or weak base?

Methylamine is a slightly stronger base than ammonia. The methyl group is electron-donating, which increases electron density on nitrogen, making the lone pair more available for proton acceptance.

FormulaCH₃NH₂
NameMethylamine
CategoryWeak base
pKa10.66
ConjugateMethylammonium ion (CH₃NH₃⁺)
Key ConceptOrganic base, compare with ammonia

Definition

Methylamine is a weak Bronsted-Lowry base. Its nitrogen lone pair accepts protons from water. The methyl group makes it a slightly stronger base than ammonia.

Acidic Proton / Active Site

Methylamine primarily acts as a base, not an acid. The lone pair on nitrogen is the key - it accepts H+ to form CH3NH3+.

Conjugate Pair

CH3NH2 + H+ -> CH3NH3+ (methylammonium, conjugate acid). The pKb of methylamine is lower than ammonia, meaning it accepts protons more readily.

Strength Classification

Kb = 4.4 x 10^-4, making it a weak base but stronger than ammonia (Kb = 1.8 x 10^-5). The electron-donating methyl group increases basicity.

See acidic protons, conjugate base overlays, and pKa labels on interactive 3D molecules.

Explore Methylamine's Acid-Base Properties in 3D

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