A salt formed from a weak base and a strong acid will produce a solution that is:

A salt formed from a weak base and a strong acid will produce a solution that is:

• A. Acidic
• B. Basic
• C. Neutral
• D. Amphoteric

Answer: (A)

When a salt comes from a weak base and a strong acid, the cation that comes from the weak base tends to act as a weak acid in water, donating a proton to water to form hydronium. The anion from the strong acid, on the other hand, is the conjugate base of a strong acid and is effectively neutral, so it doesn’t shift the pH noticeably. The key hydrolysis reaction is something like the weak-base cation accepting a water molecule to release H3O+: NH4+ + H2O ⇌ NH3 + H3O+. This production of hydronium ions makes the solution acidic. So, the overall effect is an acidic solution.

When a salt comes from a weak base and a strong acid, the cation that comes from the weak base tends to act as a weak acid in water, donating a proton to water to form hydronium. The anion from the strong acid, on the other hand, is the conjugate base of a strong acid and is effectively neutral, so it doesn’t shift the pH noticeably. The key hydrolysis reaction is something like the weak-base cation accepting a water molecule to release H3O+: NH4+ + H2O ⇌ NH3 + H3O+. This production of hydronium ions makes the solution acidic. So, the overall effect is an acidic solution.