What happens when HF and SiO2 react? Will other toxic / hazardous substances be created as a side product? Thanks!!
Actually, it is little confusing. When I wanted to try SiF4 gas for my experiment, I found out from literature that SiF4 is hazardous gas because it can easily react with water (humidity from air) to produce HF. If so the reaction would be:
SiF4 + 2H2O - - - - > 4HF + SiO2.
However, HF is usually used as an etching agent for SiO2. It means, HF+ SiO2---> SiF6 (-2) +H3O(+).
As an answer to your question, we can say that only H2SF6 solution is forming, unless you remove water from your system no SiF4 gas will evolve.
SiF4 is toxic and corrosive. In moist air it fumes, whereby it is easily hydrolyzed to give H2SiF6 and SiO2. However, in my opinion the most toxic / hazardous substance in this system is certainly HF. Utmost care must be exercised when working with HF, especially if it is a concentrated solution (40%) or even anhydrous. It easily penetrates the skin and can lead to serious injuries.
SiF4 gas will appear and take in consideration that SiF4 is toxic and corrosive. In moist air it fumes, whereby it is easily hydrolyzed to give H2SiF6 and SiO2. However, in my opinion the most toxic / hazardous substance in this system is certainly HF. Utmost care must be exercised when working with HF, especially if it is a concentrated solution (40%) or even anhydrous. It easily penetrates the skin and can lead to serious injuries
I also have a same experience at the observation of SiF4 during my experiments. By using a glass liner in the bomb reactor for the reaction in the presence of fluorine, after the reaction, my glass liner was corroded so seriously, and SiF4 can be detected in the gas phase by GC-MS. So, it is very consistent with the conclusion of SiF4 production from the reaction of SiO2 and HF. However, I also detected a large amount of SiF2H2 both in gas phase and liquid phase of my product. What is the formation route of SiF2H2? Is there any reaction between SiF4 and HF or any possible path way?
Dear Huyen Tran Dang to my knowledge the formation of difluorosilane, SiF2H2, cannot be explained by the reaction of SiF4 with HF. The latter two compounds will react under formation of H2SiF6 (see e.g. the link cited below). I think that the formation of SiF2H2 can only be explained by the presence of elemental hydrogen, H2.
https://brainly.in/question/1115388
Dear Prof. Frank T. Edelmann Thank you so much for your helpful explanation. As you said, the formation of Si2F2H2 can only ascribed by the presence of H2, and I think it is also reasonable in my case. Because I carried out my experiments in a strong acidic solvent and according to my prediction, a radical mechanism would appear likely, thus, the presence of elemental hydrogen during the reaction is inevitable probably.
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