Weak base
Section outline
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Definition: Weak bases only partially dissociate in water, producing a relatively low concentration of hydroxide ions (OH⁻).
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Characteristics:
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Incomplete ionization in aqueous solutions.
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Moderate pH, typically between 8 and 11.
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Less effective at neutralizing acids compared to strong bases.
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Examples:
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Ammonia (NH₃)
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Methylamine (CH₃NH₂)
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Pyridine (C₅H₅N)
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Reaction Example:
(Only a small fraction of ammonia molecules react with water.)
Key Differences:
Property Strong Base Weak Base Ionization Complete Partial pH Higher (above ~12) Moderate (8–11) Strength in Reactions Very high Lower Examples NaOH, KOH, Ca(OH)₂ NH₃, CH₃NH₂, C₅H₅N
Summary:
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Strong bases fully dissociate and are highly reactive.
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Weak bases partially dissociate and are less reactive but still alkaline.
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