[apienx]

Tears contain chloride ions (>100 mEq/L). I'd be worried about chlorine gas generation (a toxic gas that goes after the respiratory system, eyes, and skin). Electrolysis of water starts at potentials as low as 1.23V (the paper reports 2.2-3.3V).

[thaumasiotes]

For the same reason they contain chloride ions, they also contain sodium ions.

Are we worried about the sodium in the tears reacting with the water, and exploding?

If we managed to react the chlorine and get it out of the water, would we be worried about the sodium exploding then?

(I don't know anything relevant. So I know that salt water spontaneously exploding is a non-issue, but I don't know why that is, and I also don't know how plausible it is to worry about catalyzing the release of chlorine gas from salt water. But the questions seem vaguely related, in my totally uneducated view.)

[syndicatedjelly]

Sodium (Na) in its pure state desperately wants to give away its electron. It will react with anything where it can dump electrons (e.g. H2O).

Upon meeting water, sodium (explosively) releases its electron to water, lowering its energy state to a more favorable state. The extra electron in the water serves to split H2O into H+ and -OH ions. After releasing it's electron, sodium becomes sodium ion (Na+).

Sodium ions (Na+) can only exist in solution. In the case of water and table salt, H2O + NaCl -> H2O + Na+ + Cl- . In other words, adding salt to water produce sodium ions and chlorine ions. Both of these forms are stable in solution, because they have their desired number of electrons (and are at in their most favorable energy states). At no time was sodium (Na) involved in the equation - rather, it's stable ion form (Na+) was involved.

As an aside: You can generate chlorine gas (Cl2) by running electricity through salt water. Sodium Hydroxide (NaOH) is also generated, but is immediately split into Na+ and -OH since the generation of NaOH occurred in solution. The -OH makes the water more basic as a result. It would be a good exercise to look into why that is. NaOH loves water - it will suck it right out of the air.

Haven't stretched that chemistry muscle in nearly 15 years...Hope I didn't pull it!

[thaumasiotes]

> Upon meeting water, sodium (explosively) releases its electron to water, lowering its energy state to a more favorable state. The extra electron in the water serves to split H2O into H+ and -OH ions. After releasing it's electron, sodium becomes sodium ion (Na+).

Something seems out of balance here. Water would form H+ and OH- ions in the absence of an additional electron. Once the donation from the sodium occurs, is it forming H+ and OH²⁻?

[syndicatedjelly]

You’re right, I sort of hand-waived thru the equation. The stoichiometry was off

[automatic6131]

>So I know that salt water spontaneously exploding is a non-issue

Because the sodium as dissolved in water is already at its lowest chemical energy state. Elemental sodium, very high energy, like a ball on a high shelf. Ionised sodium, like in salt water, is that same ball on the floor. Not going anywhere.

That's the why. And why we also don't worry about table salt spontaneously releasing chlorine ions - unless we introduce something unusual like bleach.

[syndicatedjelly]

    I'd be worried about chlorine gas generation

Is this worry based in knowledge of the problem space, or knowledge of what a chlorine ion is?