kemikallyimbalanced - 1-5-2007 at 22:40
If a reacetion says to acidify something that means that the pH should be at 8 always? And if it says netralize that always means 7? Also when a
reaction tells the chemist to use for example dilute HCl or some other acid does that mean 5%?
Nicodem - 1-5-2007 at 23:37
To "acidify", not really surprisingly at all, only means that you add acid until you get an acidic reaction to whatever indicator you use (ph 8 is
basic media, not acidic!).
Similarly, to "neutralize", only means that you add so much acid or base (depending at which pH you start) as to get a neutral reaction to whatever
indicator you use.
Both terms say nothing about to which pH should one go, just to which side should one adjust the acidity/basicity. If it is important to set the pH to
a certain value then this is always additionally explained (like: "acidify to pH 3.5", etc.) except if it is self evident that the reaction or workup
media does not suffer extremes.
kemikallyimbalanced - 2-5-2007 at 17:13
Oh, I meant to say 'if a reaction says to acidify something that means that the pH should be at 6 always?' So, what about when a reaction calls for
dilute acid washes? That's like pH 3-5?
Blind Angel - 2-5-2007 at 20:18
dilute acide wash are based on commercial concentration, which pH cannot be mesured by normal scale usually (at least for strong one). Usually it mean
that you take 1 part of acid and put it into 1/2/3/... part of water, these are usually told has 1:x where 1 is the acid part and x is the water part.
Dilute acid washes really depend on what you are making and the acid that you are using, by itself it doesn't really mean anything, but your guess of
5% would be, IMO a good bet, not too strong to induce side reaction and just enough acidic to wash excess base.
kemikallyimbalanced - 5-5-2007 at 03:40
Thanks for the info.