Water to Acid vs Acid to Water

[PoolDoc]

The demo I saw of a drop of water dropped into a beaker of HCL resulted in a very violent explosion.

Was that lab acid, or 31% commercial acid?

I'm going to have to try that.

[PoolDoc]

Hm-mh. Still going to try it, but this video shows exactly what I would have expected (somewhat obnoxious sound). with commercial muriatic acid and water:
https://www.youtube.com/watch?v=hMnwhifRPuw

Mind you, the situation would be very different with sulfuric acid, where the reaction would be strongly exothermic. I haven't worked with other acids, outside of a lab.

[BigDave]

Perhaps the demo was with H2SO4 - not what I recall but it's been more than 35 years. It did make an impression on me. To this day I trust A->W and will likely continue to recommend it until there's a good reason to do otherwise.
I'll have to try it this summer when it's time to adjust my pool's pH.

[JimK]

Was that lab acid, or 31% commercial acid?

I'm going to have to try that.

Don't know. I wouldn't recommend trying it. Look it up on YouTube instead.