salt and milk:

[lnr]

didn't work. Was OK for half an hour or so but then had the nastiest bit of acidyness I've had in ages. Oh well. Rather better today. Oh yeah, and my wrist is almost entirely back to normal too, which is cool.

Comments

[sweh.livejournal.com]

http://digestive.niddk.nih.gov/ddiseases/pubs/gerd/

"Antacids, such as Alka-Seltzer, Maalox, Mylanta, Pepto-Bismol, Rolaids, and Riopan, are usually the first drugs recommended to relieve heartburn and other mild GERD symptoms. Many brands on the market use different combinations of three basic salts--magnesium, calcium, and aluminum--with hydroxide or bicarbonate ions to neutralize the acid in your stomach. Antacids, however, have side effects. Magnesium salt can lead to diarrhea, and aluminum salts can cause constipation. Aluminum and magnesium salts are often combined in a single product to balance these effects.

Calcium carbonate antacids, such as Tums, Titralac, and Alka-2, can also be a supplemental source of calcium. They can cause constipation as well."

I can't see how NaCl and milk would produce anything that would bind with the hydrogen (what causes the acid) to counter it. Probably it just caused a small lining on the stomach which acted as a temporary barrier.

[catyak]

I was trying to work that out as well. The best I can come up with is that the milk is merely there as an agent to get the salt to go down and the salt is in an attempt to increase the Cl- ion concentration, causing the H+ concentration to decrease (vague memories of [H+][Cl-] remaining constant so increasing one by adding from another source will decrease the other)

However, too much sodium is probably not a good idea.

D

[sweh.livejournal.com]

Adding Cl- wouldn't affect the concentration of H+ unless then combined to make HCl - but HCl dissolves in water and is, in fact, hydrochloric acid!

The typical student experiment is to take molar concentration Hcl and NaOH (Sodium Hydroxide) and mix them 1:1 to make NaCl + H2O (ie salt water).

This is why the typical anti-acids have hydroxide (or bicarbonate; a similar thing happens). The OH- binds tightly to the H+ to make H2O, leaving the remainder to form as a dissolved salt.

(umm, poor memories of O Level chemistry from 1983/4 involved in the making of this post so I may be wrong :-))

[catyak]

It's vaguely coming back to me now. Not sure how it'll appear on here though.

[H+][CL-]
---------- = constant
[HCl]

The concentration of H+ ions is a measure of the acidity. Common salt, NaCl, will reach its own equilibrium in a similar manner. However, putting the two together will mean the [Cl-] from one will affect the other and so decrease the concentration of [H+] to maintain the constant.

However, my O level chemistry was 1980 and A level in 1982 so even longer ago than yours. Any chemists reading who can give a definitive answer?

D

[sparrowsion]

I've got second-year undergrad chemistry from 1990, but it's still rather rusty. What I do remember is that the term describing this effect is "buffer solution" and the effect is only really noticable if the dissociation constants aren't too extreme (ie there's a significant concentration of both molecules and ions). NaCl and HCl both have pretty high dissociation constants, hence you won't see much buffering effect. (pH, BTW, is something like -log(dissociation constant), and is ρK having gone through Latinisation and German chemists, IIRC.) Hopefully ptc24 will be along to correct me shortly.

[imc.livejournal.com]

[Excuse me for jumping in to state the obvious]

pH is minus the log of the molar H+ ion concentration. Bases with high dissociation constants will have high pH while acids with high dissociation constants will have low pH.

I understand there is also a pKx for measuring the dissociation constant of particular substances x.