acidic and basic salts

[Sophia Dinh 1D]

How can you tell what salt will affect ph?

[romina_4C]

When a salt dissociates, the cation and anion can form a weak acid/base when it reacts with water. For example, when NaCl dissociates, it forms Na+ and Cl-. Na+ reacts with H2O to form NaOH, a strong base. Since it is a strong base, NaOH will fully dissociate in water again to reform Na+ and OH-, thus not affecting the pH. Cl- will also react with H2O to form HCl, a strong acid. Since it is a strong acid, it will fully dissociate in water to reform H3O+ and Cl-, thus not affecting the pH. The pH will only be affected when a salt dissociates and the result acid/base formed is weak. For example, is NH4Cl is dissociated, it will form NH4+ and Cl-. NH4+ will react with water to form H3O+ and NH3. Since NH3 is a weak base, it will not fully dissociate. And since this reaction forms H3O+, it will result in the solution becoming more acidic. The Cl- does not affect the solution for the same reasons as mentioned above.

[Daria MacAuslan 1H]

Salts usually only affect pH if they are weak rather than strong. Strong acids and bases can disassociate totally, and they wont affect the pH, while a weak one will only disassociate partially, meaning that the concentration of H30+ or OH- molecules will increase or decrease depending on the compound. this causes a change in pH.

[George Hernandez 3I]

If the salt in question was formed by a strong acid and strong base, then it will be a neutral salt (i.e. HCL + NaOH => H2O + NaCl), however if a weak acid or a weak base was used, then the resulting salt will be an acidic salt or a basic salt, respectively.