Question

1. why is sodium ion chosen as the cation of all three solutions that will be used for identification of ions? (5marks)

____sodium ion are chosen as the common cation in solution for identifying other ions. primarily because all common sodium salts are soluble in water.____

Explanation:

To determine why sodium ion is the chosen cation, we analyze its properties. Sodium salts (like NaCl, Na₂SO₄) are generally soluble in water (following solubility rules: most sodium - containing compounds are soluble). This solubility means that when we use solutions with Na⁺ as the cation, the sodium ion will not form a precipitate with the anions we are trying to identify. If we used a cation that forms a precipitate with the target anions, it would interfere with the identification process. For example, if we used Ag⁺ as the cation, it would form precipitates with many common anions (like Cl⁻, Br⁻, I⁻, CO₃²⁻) and make it impossible to accurately identify the anion of interest. Also, sodium is a relatively unreactive metal ion in terms of redox reactions under normal aqueous conditions for ion - identification experiments, so it doesn't participate in unwanted redox reactions that could complicate the identification of other ions.

Answer:

Sodium ion is chosen as the cation for ion - identification solutions mainly because: 1. Most sodium salts are soluble in water, so \(Na^+\) will not form a precipitate with the anions being identified, avoiding interference in the identification process. 2. \(Na^+\) is relatively unreactive in redox reactions under typical aqueous conditions for these experiments, so it does not participate in unwanted redox reactions that could complicate anion identification.