Q. Explain about Monohalides?

Monohalides of the type M₂X₂, (where X = F, C1 and Br) are formed only by 0. S and Se. Oxygen monofluoride decomposes above 25 K. These monohalides have got structures similar to H₂, O₂, having E-E bonds.

Monohalides of Te and Po are not formed because Te-Te and Po-Po bonds are not stable.  The monohalides are slowly hydrolysed to give the oxoacid,

2Se₂Cl₂+ 2H₂O -------------------> H₂SeO₂+ 3Se+ 4HCl

Sulphur can readily be dissolved into sulphur monochloride. S₂, CI₂ to give chlorosulphanp s,  such as. S₃ CI₂ , S₄,Cl₂ and so on upto S₁₀₀ CI₂.