Gravimetric Prac - Finding amount of Sulfur in fertiliser question

[VCEMan94]

Why does the experiment require the adding the HCl and heating the solution?
sorry if this seems like a silly question, just a bit confused

[Vincezor]

I believe the HCL is added in order to make sure none of the OH^- ions present in the solution react with the BaCl₂ used later on - As you already know the BaCl₂ is added in order to form the precipitate, BaSO₄(s)

As for heating the solution, I am not 100% sure, but I think it has something to do with increasing the reaction rate...