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salts of weak acids and bases

Posted: Sat Dec 08, 2018 3:49 pm
by Saachi_Kotia_4E
can someone explain why salts of weak bases produce acidic solutions and salts of weak acids produce basic solutions?

Re: salts of weak acids and bases

Posted: Sat Dec 08, 2018 5:58 pm
by 605168557
Basic salts form from the neutralization of a strong base and a weak acid. For example, the reaction of sodium hydroxide (strong base) with acetic acid (weak acid) will yield water and sodium acetate which is a basic salt. Similarly, acid salts form from the neutralization reaction between a strong acid and a weak base. For example, hydrochloric acid (strong acid) reacting with ammonia (weak base) produces water and ammonium chloride, which is an acid salt.

Reminder: If Ka(cation)=Kb(anion) the solution of the salt will be neutral.

Re: salts of weak acids and bases

Posted: Sat Dec 08, 2018 6:01 pm
by Porus_Karwa_2E
Will this be on the chem14A final?

Re: salts of weak acids and bases

Posted: Sat Dec 08, 2018 6:07 pm
by paytonm1H
Since salts as acids and bases are weak, there probably won't be much on the final asking about them (Lavelle said that we will only be tested on strong acids and bases, weak will be covered more in 14B). Conceptually, I believe we should know that salts containing acids will lower the solution pH and salts containing a base will raise the solution's pH.
Hope this helped!

Re: salts of weak acids and bases

Posted: Sat Dec 08, 2018 6:12 pm
by Leela_Mohan3L
A salt of a weak acid contains a strong conjugate base as its anion. This strong conjugate base is good at pulling a proton off H2O and thus OH- ions will be produced, making the solution basic. A salt of a weak base contains a strong conjugate acid, which is good at giving protons to H2O. This will produce H3O+, thus making the solution acidic.