Question

Which method is used for preparing arsenic sulfide sol?

Answer 1

Arsenic Sulfide $\left({\mathrm{As}}_2{\mathrm{S}}_3\right)$:

• Arsenic trisulfide is an inorganic substance with the formula ${\mathrm{As}}_2{\mathrm{S}}_3$.
• It is a solid that is dark yellow and insoluble in water.
• It features intrinsic phase-change characteristics and is a group V/VI intrinsic p-type semiconductor.

Preparation of Arsenic sulfide sol:

• Arsenic sulfide$\left({\mathrm{As}}_2{\mathrm{S}}_3\right)$ sol is a lyophilic sol in which the particles of the dispersed phase have negligible interactions with the dispersion medium.
• Hydrolysis of Arsenic oxide $\left({\mathrm{As}}_2{\mathrm{O}}_3\right)$ in boiling distilled water produces Arsenic hydroxide$\left(\mathrm{As}{\left(\mathrm{OH}\right)}_3\right)$on which further ${\mathrm{H}}_2\mathrm{S}$ gas is transported and leads to the formation of Arsenic sulfide sol$\left({\mathrm{As}}_2{\mathrm{S}}_3\right)$.
• The chemical reactions can be depicted as:

${\mathrm{As}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)\hspace{0.17em}+3{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to 2\mathrm{As}{\left(\mathrm{OH}\right)}_3\left(\mathrm{aq}\right)$

$2\mathrm{As}{\left(\mathrm{OH}\right)}_3\left(\mathrm{aq}\right)+3{\mathrm{H}}_2\mathrm{S}\left(\mathrm{s}\right)\to {\mathrm{As}}_2{\mathrm{S}}_3\left(\mathrm{s}\right)+6{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Thus, Passing ${\mathrm{H}}_2\mathrm{S}$ in ${\mathrm{As}}_2{\mathrm{O}}_3$ is the method used for preparing arsenic sulfide sol.