Question

Of the compounds ${\mathbf{PtF}}_{\mathbf{4}}$and${\mathbf{PtF}}_{\mathbf{6}}$, predict (a) which is more soluble in water and (b) which is more volatile.

Short answer

(a) ${\text{PtF}}_{\text{4}}$is more soluble in water.

(b)${\text{PtF}}_{\text{6}}$ is more volatile.

Step-by-step solution

Solubility

Solubility constitutes the greatest amount of solute solubilized in a particular solvent. It is based on the nature of solute and solvent.Ionic compounds possess larger solubility than covalent compounds.

Volatility

The volatile nature of a particular substance indicates that it can be transformed into a gaseous state from a liquid state. It is based on the melting point and the attractive force between the molecules and ions. The compound comprising a lower melting point is more volatile.

Solubility of PtF4and  PtF6

The solubility rule states that “like dissolves like” which indicates that the polar molecule can be dissolved in a polar solvent. The non-polar molecule can be dissolved in a non-polar solvent. Ionic compounds are more soluble in water when compared to covalent molecules. As the oxidation number of platinum increases, the covalent character also increases. In the case of and , the oxidation number of Pt is +4 and +6, respectively. PtF₄is more ionic than PtF₆, hence more soluble in water.

Volatility of PtF4 and Ptf6

An ionic compound has stronger forces of attraction when compared to a covalent compound. exhibits covalent nature as compared to due to the high oxidation number. Therefore, PtF₆ is more volatile than PtF₄.