[HoneyBadgerMS]

I'm stumped by this lab which I was assigned recently. In it I must:

  design a simple test to identify which ion (Ca²⁺, PB²⁺, Ba²⁺, Zn^²⁺, SO₄^2-, PO₄^2-, Cl^-, or I^-) is present in a sample of water. For the experiment I will be given a specific sample of water and told which ion, out of four possible ones, it may contain.

2) I must design an experiment to test the effectiveness of three filtering methods (coffee filter, your-own designed filter, and a Britta filter) at removing the ion present in your sample.


So basically I just want to know, after the water has passed through the filters, what should I be looking for(precipitate) and how would I determine what ion has been filtered out by looking at what has been left behind.
Would using a solubility chart be at all useful in this experiment?

Obviously I would need a control for the experiment and I guess that that would be the unfiltered water, since I need to be able to determine which ions were filtered out and to what degree was it effective.

[Borek]

Google for qualitative inorganic analysis (or qualitative cation analysis).

Trick is, you won't be able to detect some of the ions even if they are present, as the methods used for qualitative analysis are not that sensitive, they assume quite large concentration of ions. Plus, they won't tell you anything about the concentration change (which is the measure of the filter effectiveness). To do things correctly you would need to use a technique like AAS, which in turn requires access to the specialized hardware - which I assume you don't have.