[camurgo]

Hi, I'm an engineering dropout (planning to go back), my background in chemistry isn't so strong but I'm deeply interested.

I'm trying to understand the reaction between lime sulfur and hydrochloric acid (HCL).
It is said that lime sulfur is composed mainly of calcium polysulfides, of general formula CaS_x, where x varies from 2 to 7. (That is, CaS₂,CaS₃,CaS₄,CaS₅...) It is also said that the reaction between lime sulfur and HCL produces copious amounts of hydrogen sulfide (H₂S). But how exactly does this happen?

Wouldn't it make more sense that hydrogen polysulfides (H₂S₂, H₂S₃, H₂S₄, H₂S₅..) and calcium chloride (CaCl₂) were the products?

The equations I imagine should be:
 CaS_x + 2HCL -> H₂S_x + CaCl₂  (where, in both counts, x varies from 2 to 7)

Could it be that hydrogen polysulfides are in fact being produced but some type of disproportionation reaction is breaking them down into H₂S ?

Would anyone know anything about this?
Thank you.

[chenbeier]

The Polysulfides are not stable in acidic environments.
You will get sulfur.

CaS_x + 2HCl => CaCl₂ +H₂S + (x-1) S