this post was submitted on 02 Aug 2023
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Interesting

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[–] [email protected] 4 points 1 year ago* (last edited 1 year ago) (4 children)

Something that always confused me, as the water seems to react with bubbles when I throw salt into it. My theory is that little amount of energy gets released when the ion grid structure is broken up, but still boiling point is higher for salted water. Could absolutely be bullshit... maybe someone can explain?

Edit: Thank you all guys for taking the time to explain!

[–] cynar 5 points 1 year ago

It's likely nucleation. Basically, the water wants to boil, however it can quite get over the hump to produce a gas bubble. When you add salt, the surface acts as a nucleation point. Once the bubble forms, it grows rapidly, often splitting and forming more.

You see this effect at the other end too. Supercooled water will remain liquid, until something becomes available to crystallise around. When this happens, the whole lot will freeze in seconds.

[–] chuckleslord 2 points 1 year ago

More water vapor made when you throw in salt when it's actively boiling? Likely a physical reaction rather than a change to boiling point. The surface of the salt is rough, creating more surface area for the molecules to turn into their gaseous form.

Similar to mentos and diet coke, gases suspended in liquid can be released more efficiently with rough surfaces.

[–] CallMeTHELazer 2 points 1 year ago

It's just adding a bunch of extra surface area so the bubbles form on it. Like mentos and coke. https://youtu.be/QW7r2RHt6tY