1. The problem statement, all variables and given/known data I undertook a practical experiment where a back titration was used to determine the amount of nitrogen in fertiliser.My titres are 3.9, 3.7 and 4.2 So I know this reaction occurred: NH4+ + OH- ---> NH3 +H2O I then boiled the solution to expel the Ammonia and the excess OH- ions were titrated against 0.1 M HCl. OH- +HCl ---> Cl- +H2O Is this equation correct? If so are the following calculations correct too? n (HCl)= 0.1 x 0.0039 n(HVl)=0.0039 If this calculation is correct, what do I have to do next?