What's the ideal acid concentration?

Topic created by BrewNovice
on Fri, 1 Oct 2021 at 00:12

BrewNovice said on Fri, 1 Oct 2021 at 00:12...

The guide uses 37% HCL. What's an ideal concentration of H2SO4 for this reaction?

TheMaster (Baiter) said on Fri, 1 Oct 2021 at 01:02...

0% H2SO4

HCL is cheap and readily available. Tech grade suffices. You can also source 32% since you end up diluting it anyways no harm no foul. Just need to redo the math.

BrewNovice said on Fri, 1 Oct 2021 at 01:08...

@TheMaster I have highly concentrated H2SO4 that I need to dilute. Is this going to be problem, or is it just more trouble than it's worth. I'm hoping the quality will improve the final product, but I don't know by how much.

BrewNovice said on Fri, 1 Oct 2021 at 02:01...

I've been doing a bit more research. I made a mistake. Diluting my own highly concentrated H2SO4 is a terrible idea. Too dangerous given the strength of the acid and not worth the risk.

Thanks again for the advice @TheMaster! Glad I didn't make that mistake and I hope no one else does either.

I'm going to source some HCL and redo the math depending on the concentration I'm able to get.

Nitritespecialist said on Fri, 1 Oct 2021 at 14:09...

@Brew...the biggest problem with sulfuric is that at cold temps during the reaction, the precip becomes so thick that it impedes stirring and you need a super strong magnet to overcome it. I've also experienced a lot of foaming...not sure why.

The Professor said on Fri, 1 Oct 2021 at 16:55...

This reaction is very sensitive; it's a bit difficult to get control of the reaction, but a few things help, and after you have reaction control, you're in the water.

Data logging your own reactions will help greatly with this. Reaction speed is critical, and should be very slow and cold for repeatable results.

You control the reaction speed with the cooling bath temperature, the drip rate of the dropping funnel, the concentration of the HCL and the stir bar speed.

wrt acid concentration;37% is a very concentrated acid; you don't want to introduce such a concentrated reactant into such a small space as a drop.

Again, data logging will help you determine the ideal concentration for YOUR reactants; i suggest starting with a 30% concentration or so; if there are ANY drops that result in a foaming reaction, then dilute a bit.