Question

What experimental evidence would allow you to determine whether ${\mathbf{TiCl}}_{\mathbf{4}}$ is an ionic compound or a covalent compound? What would you predict based upon oxidation state?

Short answer

The experimental evidence that could determine whether${\text{TiCl}}_{\text{4}}$ is ionic or covalent is hardness, melting and boiling point, intermolecular forces and its solubility in water.

The oxidation state of Ti is +4 and the oxidation state of Cl is -1. Thus it appears to be ionic based on the oxidation state but is covalent in nature.

Step-by-step solution

Ionic compound and covalent compound

Ionic compounds are created when a metal fuses with a non-metal. Covalent compounds are created when two non-metals fuse with each other.

Experimental evidence needed to determine whether is an ionic compound 

The oxidation state of Ti in${\text{TiCl}}_{\text{4}}$ is:

$\begin{array}{rcl}& & \text{x - 1}\times \text{4 = 0}\\ & & \text{x - 4 = 0}\\ & & \text{x = 4}\end{array}$

The experimental evidence that could determine whether ${\text{TiCl}}_{\text{4}}$is ionic or covalent is hardness, melting and boiling point, intermolecular forces and its solubility in water.

Ti and Cl have very less interactions (weak Vanderwaals forces) and possess very low melting point of$-24.1°\text{C}$ . These evidences suggest that ${\text{TiCl}}_{\text{4}}$is covalent in nature. Hence, it is a molecular covalent compound having Ti-Cl covalent bond.

The oxidation state of Ti is +4 and the oxidation state of Cl is -1. Thus it appears to be ionic based on the oxidation state but is covalent in nature.