We did the nitrogen fertiliser back titration...
Our sodium hydroxide solution was boiled to get rid of the ammonia and then immeditely titrated with HCl. Does the tempertaure of the solution affect the titration in anyway?
oh and we also heated our BaSO4 precipitate in the gravimetric analysis prac (sulfur in fertilier) and then the solution was filtrated and the precipitate was collected.
Does this have any effect on the results?
Also with the titration graph... if you're titrating a strong base against a strong acid (base in flask, acid in burette) will the graph start at around 14 and end at around 1??? So the equivalence point should be around 7-7.5?? We used phenophalein as an indicator... and I don't think it was the most suitable choice as an indicator because it changes colour at ph8-10