Skip to main content

Identifying bronsted acids/bases

Submitted by Roger38 on Tue, 01/26/2010 - 00:38

In each of the following acid-base reactions, identify the Bronsted acid and base on the left, and their
conjugate partners on the right:
(a) HS- + C5H5NH+ -> H2S + C5H5N
(b) HAsO32- + H3PO3 -> H2AsO3- + H2PO3-
(c) (CH3)2NH2+ + OH- -> (CH3)2NH + H2O

Any help is welcome.. I'm stuck doing these.

A Bronsted acid is defined as a proton donor. A Bronsted base is defined as a proton acceptor.

HS- ---> H2S and so a proton is needed, So HS- is a Br. base
C5H5NH+ ---> C5H5N so lose a proton = Br. acid

H2S is the conj acid and C5H5N is the conj. base

So look at which reactant is losing a proton (= Br. acid) and which substance is gaining a proton (Br. base)