this advice is specifically about sulfuric acid. it’s denser than water, so if added to it it will sink diluting itself along the way, while also heating water around and making it float to the surface. if done opposite way, water won’t mix immediately because of large density difference so neutralizatio heat will be deposited on surface between these two boiling water and throwing acid around. this matters less with other acids because less heat is deposited, and in some cases acid is less dense than water. but if you stir the acid quickly, you can do it either way as long as you control temperature. this also is the case when you need to mix two different acids
tldr you can do whatever you want as long as you know what are you doing
e: i’ve checked and heat of dilution is greatest for sulfuric acid, liquid HF is similar per gram, gaseous HCl and HBr are half of that per mol, other common acids 5-10x less esp as aqueous solutions and not neat. also the same happens when diluting acids with other solvents, like alcohols or ethers, these might be even worse because they boil at lower temperature
Even though you don’t have to for all acids, it’s good practice to always add acid to water just in case you grab the wrong acid.
if you do that you have bigger problems
tldr you can do whatever you want as long as you know what are you doing
That’s how i feel about cooking
Bought a rotisserie chicken yesterday I still got half of. I plan on making up some rice with the bag juice and some veggies. I do not have any clue what I’m doing, so it’s always an experiment.
If I may, I highly recommend taking your scraps and simmering it into a bone broth, then using that to make the most exquisite rice
Not only may you, but thank you as well!
You are welcome!
only if you take notes
::Adam Savaging intensifies::
In german we say “Zuerst das Wasser dann die Säure, sonst geschieht das ungeheuere”
In rough translation “First the water, then the acid, otherwise, the unhoneyed things happens”
In Finnish we have “ensin vesi, sitten happo. Muuten tulee sormeen rakko”
Translation: “first water, then acid. Otherwise finger gets a blister”
I love that understatement
In the chem labs I took as a student…the mantra was just “AAA: Always add acid”
Always Be Chemistry
I learnt it in English as “do what you oughta, add acid to water.”
otter* 🦦
Oh I get it, adding water to acid kills the acid, but adding acid to water will put you in the hospital
Sort of like magnets, yes. 😞
But a glass of water stops magnets.
Indeed. It is science.
Erst das Wasser, dann die Säure, sonst geschieht das Ungeheure.
Erst die Säure, dann das Wasser. Das ist krasser.
In case anyone want to know why is that. Acid+water = bunch of hydrogen bonds form = heats up and starts to boil. Also most acids are much denser than water, so they sink to the bottom so they spread out and the heat dissipates better. If you put water to acid, it immedialety boils up, it can float on the boiling acid.
“Do as you ‘otter’*, add acid to water”
*otter = oughtta = ought to
one less step if you are in Boston.
Do as ya otta, add acid ta watah
If you add water to acid, you get a bleve. It’s exothermic, the water flashes into steam and the acid can spatter from the explosion. I think thats right. I used to mix acid and water all the time. Ammonia and water is highly reactive as well, although NH3 is a gas. Really dangerous stuff.
I’m not sure if you’re using BLEVE right, but I admit I’m not an expert
When water flashes to steam, it expands instantly to 1700 times its liquid volume. A single drop of water will explode when it comes into contact with strong acid, splashing the acid. The acid boils the drop of water instantly, from a liquid it expands as vapor explosively.
Put the acid in the wata like you oughta
My 7th grade science teacher
I learned this playing Where In Time Is Carmen Sandiego.
Acid in the water reservoir:
