Chapter U4.1, Problem 5E

(a)

Interpretation Introduction

Interpretation:

An interpretation of the chemical equation for the reaction of HgCl₂ and EDTA must be written.

Concept Introduction :

EDTA is a chelating ligand which can make stable complex with certain metal ions.

Answer to Problem 5E

Reaction of HgCl₂ and EDTA is a complexation reaction in which Hg²+ forms complex with EDTA.

Explanation of Solution

The reaction is represented as follows:

  $HgC{l}_2\left(s\right)+C_{10}{H}_{16}{N}_2{O}_4\left(aq\right)\to Hg{C}_{10}{H}_{16}{N}_2{O}_4\left(aq\right)\left(aq\right)+4HCl\left(aq\right)$

In this reaction, Hg²+ of HgCl₂ is complexed by EDTA which is a hexadentate ligand.

(b)

Interpretation Introduction

Interpretation:

The observation of the reaction of HgCl₂ and EDTA must be explained.

Concept Introduction :

Reaction between HgCl₂ and EDTA is complexation reaction involving chelating effect of EDTA, a hexadentate ligand.

Answer to Problem 5E

Ther reaction between HgCl₂ and EDTA produces a clear solution.

Explanation of Solution

The reaction is represented as follows:

  $HgC{l}_2\left(s\right)+C_{10}{H}_{16}{N}_2{O}_4\left(aq\right)\to Hg{C}_{10}{H}_{16}{N}_2{O}_4\left(aq\right)+4HCl\left(aq\right)$

As seen from the reaction, one reactant (HgCl₂)issolid. After the reaction it is producing a complex which is soluble in water. Thus, after the reaction, no solid residue will be left.