HSC 2003 Q27 a) (1 Viewer)

[Doogsy]

Ok, I read somewhere else in the forum that someone got the answer 78% or there abouts. I keep coming up with the answer of 24%.
Could anyone explain to me what im doing wrong.
My current method:

% S in BaSO4
S/(Ba + S + 4xO) = 13.75%

Amount of S in BaSO4 = 0.1375 * 1.8 = .2475g

% S content of fertizlizer = .2475 / 1.0 * 100 = 24.75%

Is this right?

 

[Paroissien]

It is sulfate content. No sulphur

 

[Tommy_Lamp]

Yes, as Paroissien said, you are determing the SULFATE content, not SULFUR, hence the chemical formula would be SO4, which would change your answer considerably.

 

[Doogsy]

i see... thanks, I always misread questions. I don't know why we did Sulphur content prac in class then.

 

[Tommy_Lamp]

Either your teacher misread the syllabus also or your remembering incorrectly