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Martinjg_ge OP t1_jee6b7e wrote

Reply to comment by ECatPlay in During Electrolysis of Water, what happens to oxygen at the cathode and hydrogen at the anode? by Martinjg_ge

thank you very much i always thought of water as a pot of rice, of fixed, unchangable, determined molecules. so "water" is not just a mix of water, but it's own dynamic system comparable to how in metal electrons just fly around, just that not the electrons but also entire molecules of H and O just swap back and forth.

thank you so much for taking the time to explain it to me!

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ECatPlay t1_jefce04 wrote

> i always thought of water as a pot of rice, of fixed, unchangable, determined molecules

Well you aren't wrong, it all depends on the timescale you are thinking about.

Water molecules are constantly in motion. This is what 1 picosecond of movement in a water droplet at 0 C looks like. They do move around a lot, and a lot of collisions take place in between even diffusion controlled reactions like H-abstraction (timescale 10^(-9) sec).

But relative to molecular vibrations, for instance, they are barely moving at all. Bond stretching vibrations (O-H stretch timescale ~10^(-13) sec), are orders of magnitude faster than collisions. And electronic transitions are several orders of magnitude faster than that (timescale ~10^(-15) sec), so thinking of the atoms and molecules as "fixed" in space would be an excellent picture of them on that timescale. Thinking about an electrical conductor, instead of an H^+ transfer medium, for instance.

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