Biology Forums - Study Force

Science-Related Homework Help Chemistry Topic started by: smn on Feb 14, 2013



Title: How do I determine if a precipitate is formed?
Post by: smn on Feb 14, 2013
For instance, in
3Ba(OH)2(aq) + 2H3PO4(aq) --> Ba3(PO4)2(s) + 6H2O(l)

How do I know if one has formed? You don't have to tell me if it did or didn't, I just want to know what the process of determining this is.


Title: How do I determine if a precipitate is formed?
Post by: michele 84 on Feb 14, 2013
In general you will need to refer to the solubility rules - which will tell you which compounds are insoluble. Then if one of the possible products of a double displacement reaction is insoluble a precipitate will form. In the reaction you give the precipitate is the solid Ba3(PO4)2(s).


Title: How do I determine if a precipitate is formed?
Post by: tony3320 on Feb 14, 2013
You need to know the solubility product (Ksp) and then if the concentrations exceed that, you will get a ppt.  If the concentrations do not exceed that value, you will not get a ppt.