Hi.
In the follow link:
https://shorturl.at/fvhwX
There is a description how to make surgical mask
meets the standard of N95 mask by sealing the sides with 2 rubber bands.
I wonder if it really gives a protection against airborne particles as N95 mask(at least close to),just by sealing it.
What about the fabric itself,Does the fabric of the surgical mask has the ability to protect against airborne particles like the fabric of the N95 mask,while the only problem of the surgical mask was the sealing issue(which now is solved by 2 rubber bands)?

We have been trying some test reactions using previously obtained protocols (one from the 1930s), and the preliminary H-1 results from the first protocol is very promising. Today I found the two papers below, which use TFA and a metal-ion salt of nitrate or nitrite.  We are looking for references to other TFA-based methods, just in case our first methods fail.

https://pubs.rsc.org/en/content/articlepdf/1978/p1/p19780001076
S Uemura et al., J Chem Soc Perkin I 1076-1079 1978.
https://jcsp.org.pk/ArticleUpload/1368-6161-1-RV.pdf
Munawar and Khalid 2004
From the first reference:  "A typical procedure is given. To a stirred solution of toluene (0.184 g, 2 mmol) in trifluoroacetic acid (15 ml) was added solid sodium nitrite (0.414g, 6 mmol) in one portion a t 25 "C. The resulted dark brown mixture was stirred for 8 h at 25 "C during which period the mixture turned orange, water (100 ml) was added, and the solution was extracted with benzene (3 x 50 ml)...Reactions with sodium nitrate were carried out similarly."  The substrates in the second reference were haloaromatics, and the conditions were 90 °C.  I don't think that their substrates are similar to ours, and I doubt that I would try this method as is.

I need to balance this reaction using the oxidation number change method, which I think is preferable to the half-reaction method, since the reaction is written in molecular form.
K₂CrO₄ + KI + HCl → CrCl₃ + KCl + I₂ + H₂O
I know that chromium is reduced (from +6 to +3) while iodine is oxidized (from -1 to 0).
I also know that I need to balance the iodine atoms by placing a 2 in front of KI on the reactant side.
The balanced reaction, according to the book solution, is as follows:
2K₂CrO₄+ 6KI + 16HCl → 2CrCl₃ + 10KCl + 3I₂ + 8H₂O.
I can't understand how it was solved: can someone help me?

please check my email!

You need to draw your attempts. No one is going to decipher your text.