The General Solubility Rules Must Be Used Essay example

1903 Words Jun 14th, 2016 null Page
Discussion:

As the results show, both solutions had varying degrees of success in determining the two different anions and cations contained by solutions, respectively, Solution A(anion) and Solution 1(Cation). To fully understand these results, the General solubility rules must be used:

(see bibliography: ’Precipitation Rules’)

Interpretation / justification of the unknown cation solution tests ‘1’ results:

The unknown cation solution selected was ‘1’. Firstly this solution was tested for Pb2+using HCl. This was done because as the 3rd general solubility rule on the table provided states, all salts containing Chloride are soluble, with one of exceptions being if salt contains Pb2+. Thus if Pb2+exists in the solution, a precipitate would occur when the lead cation ion mixes with the chloride anion. This test, when performed, no precipitate occurred, meaning that no insoluble PbCl2(net ionic equation: Pb2++2Cl-PbCl2) precipitate was produced. This eliminates any possibility of Pb2+ with a molarity of more than 0.05 mol/L being an ion within the unknown solution.

Next, this unknown cation solution containing the non-reactive chloride anion was split into two separate test tubes. Once split, one test tube was mixed with NaF (a F - anion), while the other with H2SO4(a SO4 -ion). Firstly, the sodium fluoride test yielded no precipitate. With NaF added in excess, the solutions dye only slightly decolourised. Thus from this result, Ca2+was not detected in solution.…

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