Equal amounts of a weak acid and a strong base are mixed. What is the resulting solution like?
AWeakly acidic, from the cation left behind
BWeakly basic, from the anion left behind
CExactly neutral, since both are used up
DStrongly acidic, from the leftover acid
Answer & Solution
Correct answer: B. Weakly basic, from the anion left behind
1. The cation here is the conjugate acid of a strong base, which has no measurable acidity.
2. The anion is the conjugate base of a weak acid, so it is itself a weak base.
3. That anion takes protons from water and raises the hydroxide concentration.
4. The solution is therefore weakly basic even though the amounts were stoichiometric.
5. Sodium acetate from acetic acid and sodium hydroxide is the standard example.
_Source: OpenStax Chemistry (CC BY 4.0), Ch 14 "Acid-Base Equilibria", section 14.4 Hydrolysis of Salt Solutions_
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