# Will silicon dioxide react with hydrochloric acid?

I have the following equation, based on the reaction of $$\ce{SiO2}$$ with $$\ce{HF}:$$

$$\ce{SiO2 + HCl -> SiCl4 + 2 H2O}$$

I want to know if this reaction is indeed feasible, what conditions may be needed to induce it, or if it isn't possible why that's the case.

• No, HCl does not etch SiO2 appreciably. – Jon Custer Jun 26 '19 at 18:39
• You can store HCl in a glass bottle. Please don't do that with HF. – Jon Custer Jun 26 '19 at 18:43
• Well, Cl is very much not like F. For this reason, the reaction is totally impossible. Or rather, it will go quite readily, only backwards. – Ivan Neretin Jun 26 '19 at 18:53
• @faissaloo - in grad school somebody really messed up a hood by being lazy and pouring HF waste into the (glass) waste bottle sitting there (for aluminum etchant). What a mess to clean up! – Jon Custer Jun 26 '19 at 19:03
• Well, they are different chemical elements; isn't that enough of a justification for any of their properties to be different? In particular, size matters. F is small, which makes the formation of $\ce{SiF6^2-}$ possible and even desirable. Not so with Cl. – Ivan Neretin Jun 26 '19 at 19:56

According to the paper by Chung and Sturm [1], $$\ce{HCl}$$ will do a very small amount of etching at high enough temperatures (525 °C will give you about 1 nm/min), but the presence of hydrogen limits the reaction because the formation of $$\ce{HCl}$$ is preferred to the formation of $$\ce{SiCl4}.$$