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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: agjfritz on July 06, 2020, 09:54:49 PM

Title: Determining measurements for concentrated brine for mineral water.
Post by: agjfritz on July 06, 2020, 09:54:49 PM

I've already got the recipe for the salts to add to my water in pursuit of the topo chico clone that I've been making. Right now I add them by weight to 5gal of RO water and carbonate/shake the hell out of it. I want to find a way to make this process easier and that's where Chemistry comes in... So I dust off the old college text book and I am way over my head... Problem goes like this:

You have 5gal of water to which you add 1.1g NaCl, 0.9g NaHCO3.... etc... This gives you a certain concentration of these salts in the water.. Got that no problem. What I want to do is dissolve as much of these salts in a much higher concentration in hot water and then use like 10ml of that instead of measuring it out every time. This seems like a more reliable method to get the right molarity (I believe I'm using that right) of salts in the final solution (10ml of brine into 5Gal water.

1) Is this really easier than just measuring it out by weight each time? We're talking 2 times a week which isn't a lot but it's usually when I'm super busy with other things.

2) I think the math I need to do is a) determine molarity of original solution. b) determine number of salt molecules in 5GAL batch. 3) determine number in 10 or 100ml dose (whatever will get it to dissolve). 4) figure amount I need to dissolve into solution. 5) solve for the chalk problem (which barely dissolves). 6) make and stir like hell.

I know these are very newbie questions but it's been a few years since undergrad chem class.

Thanks

Fritzy

Title: Re: Determining measurements for concentrated brine for mineral water.
Post by: Borek on July 07, 2020, 03:05:41 AM

Definitely measuring and diluting concentrate is easier and should in general produce the same final solution. That is, if the concentrate doesn't get past solubility limits.

And yes, your approach to calculation looks more or less correct in terms of the logic involved, however, it can be done much easier. You don't need to convert to moles. You know the final solution has to contain 1.1 g NaCl per 5 gal of water, right? So if you manage to dissolve 11 g in 100 mL of water and then measure 10 mL of that, it contains exactly the amount you need. See the difference?