A black sulphide is formed by the action of ${\mathrm{H}}_2\mathrm{S}$ on:

A black sulphide is formed by the action of ${\mathrm{H}}_2\mathrm{S}$ on ${\mathrm{CuCl}}_2$

${\mathrm{CuCl}}_2+{\mathrm{H}}_2\mathrm{S}\to \underset{\left(\mathrm{Black}\right)}{\mathrm{CuS}}+2\mathrm{HCl}$

${\mathrm{CdCl}}_2$forms yellow ppt and ${\mathrm{ZnCl}}_2$forms white ppt.

A black sulphide is formed by the action of ${\mathrm{H}}_2\mathrm{S}$ on cupric chloride.