posted by Katlyn on .
Which precipitate should react when HCl is added? Give REASONS for your prediction. The anions i have are Co3 and SO4 i wrote none of them react with HCl. I don't know what to write for the reason though please help me woth this one.
You'll need to come up with some good ones because they WILL react.
CO3^2- + 2H^+ ==> H2O + CO2
This reaction will be vigorous, yielding many bubbles and much activity in the solution. Enough HCL will dissolve all of a carbonate ppt.
SO4^2- + H^+ ==> HSO4^-
This reaction is more subtle and you may not see it at all. Several sulfates are insoluble (many are soluble) and those insoluble sulfates are MORE soluble in HCl than in pure H2O due to the formation of the HSO4^- ion in the above reaction. Not much dissolving will take place but it will dissolve some. BaSO4 is an example of this. It is more soluble in HCl but a lot of HCl still will dissolve only relatively small amounts of BaSO4.