Intheswamp wrote: ↑Sun Jul 03, 2022 12:35 pm
Ok, I'm a bit confused now. I was thinking that you only had to drip a few drops of vinegar onto a small bit of sand and if it fizzes/foams it's no good.
How large of a reaction you get would depend on a few factors, mostly the concentrations of acid and calcium carbonate. A few drops may only be enough to wet the surface of the sand, not providing a vessel for bubbles to even form, even though a reaction is taking place. If the CaCO3 concentration is high enough, you may see an initial fizz as the few drops of acid are being neutralized, but it will be short lived.
Intheswamp wrote:I then dropped a few drops of the vinegar on a pinch of garden lime and the reaction was immediate,
Because, while you used the same vinegar with an (assumed) acidity of 5%, the sand has a CaCO3 concentration of about 5%+/- (depending on the source, beach sand would have a much higher concentration), while the lime has a concentration of 95% to 100% and is a powder rather than a grain. The reaction between the vinegar and lime would be immediate, where the sand would be slow.
The best analogy I could suggest is Alka-seltzer.
Put a whole tablet in water, it fizzes for a few minutes until the reaction is done, and it has dissolved into the water. However, if you were to grind up a tablet to a powder and dump it in the same amount of water, the reaction would be immediate, and the powder would dissolve into the water in a matter of a couple of seconds.
Everything happens for a reason. Sometimes the reason is that I make bad decisions.