Question

Examine the procedure in Table$\mathbf{7}\mathbf{-}\mathbf{1}$for the Fajans titration of${\mathbf{Zn}}^{\mathbf{2}\mathbf{+}}$Do you expect the change on the precipitate to be positive or negative after the equivalence point?

Short answer

After the equivalence point, the expected change in sign of the surface charge of the precipitate is negative.

Step-by-step solution

Define Fajans methods.

The Fajans rule determines whether a chemical link is covalent or ionic. The partial covalent properties of a few ionic bonds were initially described by Kazimierz Fajans in .He was able to anticipate ionic or covalent bonding given attributes like ionic and atomic radius using X-ray crystallography at the time.

Explain the projected change in sign of the surface charge of the precipitate

There are more zinc ions present when titrating zinc ions against potassium ferrocyanide before reaching the equivalency point.

Excess zinc ions are adsorbed on the ferrocyanide ion surface, resulting in an increase in negative charge.

Greater ferrocyanide ions are present in solution beyond the equivalence point, giving the precipitate a more negative charge.

There is a change in the sign of negative charge after equivalence point due to excess ferrocyanide ions on the precipitate.