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| camear2003 |
 Posted: Sun Jun 15, 2008 8:01 am Post subject: Quick Question i cant seem to find an answer to |
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Forum Freshman
Joined: 14 Jun 2008
Posts: 4
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Stupid i know but
How come Sulphur trioxide can form (SO3)-2 and also (SO3)
And also,
why in solution is Na+ and Cl- not hydrolised
while Mg2+ is
is this just due to the charge of the Mg ion
and if so why does this form H+ ions to increase the pH?
The book im working from tends to gloss over this detail and i dont have another... |
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| SteveF |
| Posted: Sun Jun 15, 2008 6:37 pm Post subject: |
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Forum Bachelors Degree
Joined: 28 May 2007
Posts: 465
Location: NC USA
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Â
There are different electron configurations for sulfite ion (SO3--) and sulfur trioxide. Both are stable in their respective environments.
Magnesium hydroxide is only slightly soluble in water. So if you dissolve magnesium chloride, MgCl2 , there is major dissociation of the chloride ion but then Mg++ enters an equilibrium situation with water:
Mg++ +2H2O <--> Mg(OH)2 + 2H+
Thus there is created a surplus of hydrogen ions to affect the pH. All salts of weak acids and weak bases behave this way. It is the basis for buffer solutions.
By contrast, NaCl is the salt of neutralizing a strong acid with a strong base.
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| Hester |
| Posted: Wed Jun 18, 2008 1:55 am Post subject: Nicotine... |
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Forum Freshman
Joined: 17 Jun 2008
Posts: 2
Location: London
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Hi,
Would any one be able to explain me the difference between "free-base nicotine" and "protonated nicotine"?
I am a translator, and if anyone has the translation of these 2 notions in French that would great...
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| SteveF |
| Posted: Wed Jun 18, 2008 5:21 am Post subject: |
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Forum Bachelors Degree
Joined: 28 May 2007
Posts: 465
Location: NC USA
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Â
Freebase nicotine, or any freebase alkaloid, refers to the pure form of the compound. Since an alkaloid is slightly basic, it can be neutralized with HCl to obtain the HCl salt. This is the protonated form. The HCl salt is preferred for storage of the alkaloid. It is more stable and dissolves more readily.
For more information, see the Wikipedia srticle here:
http://en.wikipedia.org/wiki/Freebase_%28chemistry%29
The HCl salt may also be considered the protonated form.
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| Hester |
| Posted: Wed Jun 18, 2008 7:48 am Post subject: |
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Forum Freshman
Joined: 17 Jun 2008
Posts: 2
Location: London
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Thank you soooo much Steve... Great help!
I still have to find the equivalent in French, but it's going to be easier now... |
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| SteveF |
| Posted: Wed Jun 18, 2008 10:14 am Post subject: |
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Forum Bachelors Degree
Joined: 28 May 2007
Posts: 465
Location: NC USA
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Â
I'll not attempt any of my fractured French on this question, but you would be chemically correct to avoid translating "protonated" and give instead the French equivalent of nicotine salt, nicotine-HCl, or the amine salt. Any ofhese terms ought to be superior. It is even uncommon in English to talk of a "protonated" alkaloid. Bon chance.
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