Question

Identify Any one cation and anion from the following given salt.(a)CaCO3 (b)BaCl2 (c)ZnS (d)Pb(NO3)2 (e)FeCl3 1.physical characteristic,2.dry and wet test for cation ,3.dry and wet test for anion ,4.confirmatory test for cation and anion

Answer 1

Calcium ions form reddish brown color, barium ions form green color and potassium ferrous ions give Prussian blue color.

Explanation:

1- When calcium carbonate dissociates into ion its forms calcium and carbonate ions separately.

Calcium forms bivalent ions such as Ca2+ and when platinum is burnt in the presence of calcium salt then a spectrum of reddish brown color is observed due to the excitation of electrons from calcium ion.

2- When platinum wire is burnt in the presence of barium salt solution, then green color is observed due to the excitation of electrons from ground state to excited state of barium ion.

3- Similarly potassium ferrocyanide gives dark blue precipitates of ferric ferrocyanide.