Sulfate content in fertilizer experiment? (1 Viewer)

[leesh95]

The method that our teacher gave us says the following:
1. Weigh 1 g of fertilizer
2. Add it in 250 mL of 0.1M/L HCl and stir to dissolve as much as possible
3. Filter of insoluble material

Why do we filter it after adding the HCl?
And also why do we add HCl in the first place?

 

[7eleven]

The method that our teacher gave us says the following:
1. Weigh 1 g of fertilizer
2. Add it in 250 mL of 0.1M/L HCl and stir to dissolve as much as possible
3. Filter of insoluble material

Why do we filter it after adding the HCl?
And also why do we add HCl in the first place?

lol @ ur teacher
theres a lot more to this experiment than three simple steps

 

[leesh95]

No these are just the first 3. There is obviously more than this.

 

[someth1ng]

There's around 10 steps that should be there.

 

[someth1ng]

No these are just the first 3. There is obviously more than this.

Still, you got the first 3 steps wrong.

 

[leesh95]

Well this is what he gave us. How are they wrong?

 

[someth1ng]

The method that our teacher gave us says the following:
1. Weigh 1 g of fertilizer
2. Add it in 250 mL of 0.1M/L HCl and stir to dissolve as much as possible
3. Filter of insoluble material

Why do we filter it after adding the HCl?
And also why do we add HCl in the first place?

1. After adding HCl, there might be other precipitates such as PbCl2 that forms.
2. Addition of HCl removes carbonates (effervescence of CO2) and precipitates possible Pb/Ag contaminants that would precipitate out of solutions in the presence of sulfates.

Well this is what he gave us. How are they wrong?

You're supposed to crush the fertiliser and sometimes, you lightly heat the solution to allow more sulfates to dissolve.