Aqueous copper sulphate solution (blue in colour) gives:(i)A green precipitate with aqueous potassium fluoride and(ii)a bright green solution with aqueous potassium chloride. Explain these experimental results.

The reactions you're describing involve the addition of aqueous copper sulfate (CuSO4) solution to aqueous potassium fluoride (KF) and aqueous potassium chloride (KCl), resulting in different observable outcomes. Let's break down each reaction:

(i) A green precipitate with aqueous potassium fluoride (KF):
CuSO4 + 2KF → CuF2 + K2SO4

In this reaction, copper sulfate (CuSO4) reacts with potassium fluoride (KF) to form copper fluoride (CuF2) and potassium sulfate (K2SO4). The green precipitate you observe is the formation of copper fluoride, which has a green color. The green coloration arises because copper ions (Cu²⁺) in the CuSO4 solution react with fluoride ions (F⁻) from KF to form CuF2, which is insoluble in water and thus precipitates out of the solution.

(ii) A bright green solution with aqueous potassium chloride (KCl):
CuSO4 + 2KCl → CuCl2 + K2SO4

In this reaction, copper sulfate (CuSO4) reacts with potassium chloride (KCl) to form copper chloride (CuCl2) and potassium sulfate (K2SO4). The bright green color of the resulting solution is due to the formation of copper chloride. Similar to the previous reaction, copper ions (Cu²⁺) in the CuSO4 solution react with chloride ions (Cl⁻) from KCl to form CuCl2, which remains dissolved in the solution. Copper chloride also has a green color, giving the solution its characteristic bright green appearance.

In both reactions, the green coloration arises from the formation of copper compounds, copper fluoride (CuF2) in the first reaction and copper chloride (CuCl2) in the second reaction, both of which exhibit green colors.