Question

The correct statement for the molecule ${\mathrm{CsI}}_3$ is that

• A. It contains ${\mathrm{Cs}}^{+},{\mathrm{I}}^{-}$and lattice${\mathrm{I}}_2$molecule
• B. It contains ${\mathrm{Cs}}^{3+}$ and${\mathrm{I}}^{-}$ ions
• C. It is a covalent molecule
• D. It contains ${\mathrm{Cs}}^{+}$ and ${{\mathrm{I}}_3}^{-}$ ions

Answer 1

The correct option is D

It contains ${\mathrm{Cs}}^{+}$ and ${{\mathrm{I}}_3}^{-}$ ions

The explanation for the correct option:

Option (d) it contains ${\mathrm{Cs}}^{+}$ and ${{\mathrm{I}}_3}^{-}$ ions

Caesium Triiodide:

• Caesium Triiodide is an inorganic compound with the formula: ${\mathrm{CsI}}_3$
• Its structure is as follows:

• Caesium Iodide dissociates as:

$\underset{\mathrm{Cesium}\mathrm{Triiodide}}{{\mathrm{CsI}}_3\left(\mathrm{l}\right)}\to \underset{\mathrm{Cesium}\mathrm{ion}}{{\mathrm{Cs}}^{+}\left(\mathrm{l}\right)}+\underset{\mathrm{Triiodide}\mathrm{ion}}{{{\mathrm{I}}_3}^{–}\left(\mathrm{l}\right)}$

• Further, the Triiodide ion dissociates to give ${\mathrm{I}}_2$and ${\mathrm{I}}^{-}$

$\underset{\mathrm{Triiodide}\mathrm{ion}}{{{\mathrm{I}}_3}^{-}\left(\mathrm{l}\right)}\to \underset{\mathrm{Iodide}\mathrm{ion}}{{\mathrm{I}}^{-}\left(\mathrm{l}\right)}+\underset{\mathrm{Iodine}\mathrm{gas}}{{\mathrm{I}}_2\left(\mathrm{g}\right)\uparrow }$

• Thus, this is an ionic molecule.

So, option (D) is the correct answer.