# Fertiliser Calculations question (1 Viewer)

#### leehuan

##### Well-Known Member
Can someone please do this question and check my working/answer? The answer wasn't given. I ended up with A.

Q: A student wants to determine the sulfate content of a fertilizer.

Following a typical procedure, they obtain the results shown below.

Mass of fertilizer used = 2.34g
Mass of fertilizer that did not dissolve = 0.18g
Volume of saturated BaCl2(aq) added = 50mL
Mass of glass filter = 19.5(g)
Mass of glass filter with dry BaSO4 = 21.6(g)

What is the sulfate content of the fertilizer?
_____________
Options

(A) 40%
(B) 50%
(C) 75%
(D) 90%

_____________

My method:

Ignoring the fertiliser that didn't dissolve we have 2.16g of fertiliser to consider

Mass of the BaSO4 is 2.1g

The % composition of SO4 in BaSO4 using molar masses is (32.07+4*16)/(32.07+4*16+137.3) * 100%
= 41.1% (approx)

Our SO4 present must therefore be 41.1% unrounded * 2.1g = 0.8644g

So the % composition of SO4 in the fertiliser is 0.8644g/2.1g * 100% = roughly 40%

#### Jimmy_Arsenal

##### HSCya Later ***erator
Yup, your working seems fine man, I got 0.400555.......
around 40% of the fertiliser was SO4.

- Jimmy