From RUDNYI Fri Apr 9 14:50:57 MSD 1993 To: newsserv@newcom.kiae.su Newsgroups: sci.chem Message-Id: From: RUDNYI@mch.chem.msu.su (Rudnyi Evgenii) Date: Fri, 9 Apr 93 14:50:57 +0400 (MSD) Subject: does sulfate anion SO4(2-) exist? Keywords: negative ion Distribution: world Status: O I study inorganic negative ions in the gas phase and I like thinking on comparing the properties of pure ions and ions in the condensed phases. As for me, the main feature here is the absence of multi-charged anions in the gas phase. I'm not aware of any reliable observation of multi-charge negative ions in the gas phase at all. Apparently, multi-charge negative ions are unstable in the gas phase and it seems to be tacit agreement among chemists on that. This brings to a question what multi-charge negative ions in the condensed phases are - just a fiction or a reality. I have got a paper on that matter with example of sulfate anion SO4(2-), which is the main negative ion in the condensed phases and which does not exist in the gas phase (the gas phase ions are SO2-, SO3-, SO4-, KSO4-, K3S2O8-). Izv. Vyssh. Uchebn. Zaved., Khim. Khim. Tekhnol. 1989, v.32, N 5, p.3-12. If you need a copy (in Russian) let me know. There are no any answers and conclusions in that paper but only a collection of the facts. Actually, I don't know the answer. So I would be glad to hear from you: *What do we mean by the term SO4(2-) in the condensed phases if there is no such a stable entity?* Evgenii Rudnyi Chemistry Department Moscow State University From news-service Tue Apr 13 16:22:15 1993 To: subscribers From: tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson) Newsgroups: sci.chem Subject: [News] Re: does sulfate anion SO4(2-) exist? Message-ID: <1993Apr10.134937.26001@kth.se> Date: Sat, 10 Apr 93 13:49:37 GMT References: <40506@mch.chem.msu.su> Reply-To: tomas_e@LINK.Physchem.KTH.SE Organization: Royal Institute of Technology, Stockholm Nntp-Posting-Host: link.physchem.kth.se Sender: L-usenet@newcom.kiae.su Status: RO In article <40506@mch.chem.msu.su>, RUDNYI@mch.chem.msu.su (Rudnyi Evgenii) writes: >I study inorganic negative ions in the gas phase and I like thinking on >comparing the properties of pure ions and ions in the condensed phases. >As for me, the main feature here is the absence of multi-charged anions >in the gas phase. Is this true? What is the gas phase? I've never heard of this before. >I'm not aware of any reliable observation of multi-charge negative ions >in the gas phase at all. Apparently, multi-charge negative ions are >unstable in the gas phase and it seems to be tacit agreement among >chemists on that. This brings to a question what multi-charge negative >ions in the condensed phases are - just a fiction or a reality. I vote for reality. Check thermodynamic properties of solutions or melts of sulfates and other ionic compounds with multivalent anions. Electrophoretic mobilities and effects of multivalent anions on electrical double layers next to charged surfaces are some other phenomena consistent with multivalent anions in solution. >I have got a paper on that matter with example of sulfate anion SO4(2-), >which is the main negative ion in the condensed phases and which does >not exist in the gas phase (the gas phase ions are SO2-, SO3-, SO4-, >KSO4-, K3S2O8-). > >Izv. Vyssh. Uchebn. Zaved., Khim. Khim. Tekhnol. 1989, v.32, N 5, p.3-12. >If you need a copy (in Russian) let me know. Does this journal exist in English translation? In that case, what is its name in translation? >There are no any answers and conclusions in that paper but only a >collection of the facts. Actually, I don't know the answer. So I would >be glad to hear from you: > >*What do we mean by the term SO4(2-) in the condensed phases if there is >no such a stable entity?* I would like to ask *you*: Is there anything that indicates that the sulfate ion isn't stable in solution? If that is so, what happens when I dissolve potassium sulfate in water? If your answer is not "we get K+ and SO_4^{2-}, and some HSO_4^{2-} and OH-", please explain how that which happens is consistent with measurements of colligative and other properties of K2SO4 solutions. Btw, does this hypothesis (the nonexistence of multivalent anionic species in solution) apply to macroions as well? A DNA molecule in solution has a very large negative charge, due to the phosphate moieties between the sugar rings. Explain how that is consistent with your claim! :-) Tomas Eriksson (tomas_e@physchem.kth.se) Dept. Physical Chemistry, Royal Institute of Technology, Stockholm, Sweden From RUDNYI Thu Apr 15 22:34:57 MSD 1993 To: newsserv@newcom.kiae.su Newsgroups: sci.chem References: <1993Apr10.134937.26001@kth.se> Message-Id: From: RUDNYI@mch.chem.msu.su (Rudnyi Evgenii) Date: Thu, 15 Apr 93 22:34:57 +0400 (MSD) Subject: Re: does sulfate anion SO4(2-) exist? Distribution: world Status: O In a reply to my article <40506@mch.chem.msu.su> >As for me, the main feature here is the absence of multi-charged anions >in the gas phase. tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson) wrote <1993Apr10.134937.26001@kth.se> >Is this true? What is the gas phase? I've never heard of this before. To imagine ions in the gas phase is quite simple. Let us take potassium sulfate and heat it up to about 1300 K. Actually, we did that in our experiments. At these temperatures this substance vaporizes, i.e. it comes to the state where individual molecules are far away from each other and we can neglect any interaction among them. What entities will you find in that gaseous state? Individual molecules K2SO4 and dissociation products O2, K and SO2 in about the same concentrations. How do we know that? By means of mass spectrometry, which brings straightforward and unambiguous results. Where are the ions then? They are also there, but their concentration being seven orders of magnitude lower (in partial pressures: neutral molecules - about 1 Pa, ions - 10^(-7) Pa). What ions are there? SO2-, SO3-, SO4-, KSO4-, K3S2O8-, K+, K3SO4+ and no SO4(2-). Again, mass spectrometry shows it clearly (we measure the mass to charge ratio). Well, one may say, you'd better study the negative ions in the condensed phase. To this end, I will tell you the results of other mass spectrometry methods: FD (field desorption) SIMS (secondary ion mass spectrometry) FAB (fast atom bombardment) LD (laser desorption) field desorption from solution at atmospheric pressure. All these methods claim that they get ions right from the condensed phase (solid or liquid). This is not obvious though, for secondary processes are always possible. Nonetheless, all of these methods show the one-charged ions listed above and no SO4(2-). What we definitely can say from there? The *isolated* double-charged anion SO4(2-) is unstable, i.e. it throws away the second electron instantly, forming SO4-. By the way, all theoretical calculations confirm that. >Does this journal (Izv. Vyssh. Uchebn. Zaved., Khim. Khim. Tekhnol. 1989, v.32, N 5, p.3-12. where I wrote all mentioned above) >exist in English translation? No, I'm sorry. I don't know what all this may imply for solutions and that was my question. Evgenii Rudnyi Department of chemistry Moscow State University From news-service Wed Apr 21 09:59:36 1993 To: subscribers Newsgroups: sci.chem From: nkjrm@alf.uib.no (Rolf Manne) Subject: [News] Re: does sulfate anion SO4(2-) exist? Message-ID: Organization: University of Bergen References: <40506@mch.chem.msu.su> <1993Apr10.134937.26001@kth.se> Date: Fri, 16 Apr 93 07:18:26 GMT Sender: L-usenet@newcom.kiae.su Status: RO In article <1993Apr10.134937.26001@kth.se> tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson) writes: >In article <40506@mch.chem.msu.su>, RUDNYI@mch.chem.msu.su (Rudnyi Evgenii) writes: >>I study inorganic negative ions in the gas phase and I like thinking on >>comparing the properties of pure ions and ions in the condensed phases. >>As for me, the main feature here is the absence of multi-charged anions >>in the gas phase. >Is this true? What is the gas phase? I've never heard of this before. >>I'm not aware of any reliable observation of multi-charge negative ions >>in the gas phase at all. Apparently, multi-charge negative ions are >>unstable in the gas phase and it seems to be tacit agreement among >>chemists on that. This brings to a question what multi-charge negative >>ions in the condensed phases are - just a fiction or a reality. >I vote for reality. Check thermodynamic properties of solutions or melts >of sulfates and other ionic compounds with multivalent anions. >Electrophoretic mobilities and effects of multivalent anions on >electrical double layers next to charged surfaces are some other >phenomena consistent with multivalent anions in solution. >>I have got a paper on that matter with example of sulfate anion SO4(2-), >>which is the main negative ion in the condensed phases and which does >>not exist in the gas phase (the gas phase ions are SO2-, SO3-, SO4-, >>KSO4-, K3S2O8-). >> >>Izv. Vyssh. Uchebn. Zaved., Khim. Khim. Tekhnol. 1989, v.32, N 5, p.3-12. >>If you need a copy (in Russian) let me know. >Does this journal exist in English translation? In that case, what is >its name in translation? >>There are no any answers and conclusions in that paper but only a >>collection of the facts. Actually, I don't know the answer. So I would >>be glad to hear from you: >> >>*What do we mean by the term SO4(2-) in the condensed phases if there is >>no such a stable entity?* >I would like to ask *you*: Is there anything that indicates that the >sulfate ion isn't stable in solution? If that is so, what happens when I >dissolve potassium sulfate in water? If your answer is not "we get K+ >and SO_4^{2-}, and some HSO_4^{2-} and OH-", please explain how that >which happens is consistent with measurements of colligative and other >properties of K2SO4 solutions. >Btw, does this hypothesis (the nonexistence of multivalent anionic >species in solution) apply to macroions as well? A DNA molecule in >solution has a very large negative charge, due to the phosphate moieties >between the sugar rings. Explain how that is consistent with your claim! >:-) >Tomas Eriksson (tomas_e@physchem.kth.se) >Dept. Physical Chemistry, Royal Institute of Technology, Stockholm, Sweden The original poster raises a valid point. A system like the sulfate ion without a stabilizing exterior field will gain energy by discarding an electron. Also, there are very few stable positive molecular ions in the gas phase (if any) with a charge larger than one. They will gain energy by fragmentation. Elementary solution chemistry is full of obviously useful concepts which nevertheless are incorrect if interpreted literally. Rolf Manne Department of Chemistry, University of Bergen, Norway e-mail Rolf.Manne@kj.uib.no From news-service Wed Apr 21 09:59:36 1993 To: subscribers Newsgroups: sci.chem From: poutsmaj@mace.cc.purdue.edu (unknown) Subject: [News] Re: does sulfate anion SO4(2-) exist? Message-ID: Organization: Purdue University References: <40506@mch.chem.msu.su> <1993Apr10.134937.26001@kth.se> Date: Fri, 16 Apr 93 14:06:33 GMT Sender: L-usenet@newcom.kiae.su Status: RO In article nkjrm@alf.uib.no (Rolf Manne) writes: >In article <1993Apr10.134937.26001@kth.se> tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson) writes: > > >The original poster raises a valid point. A system like the sulfate >ion without a stabilizing exterior field will gain energy by discarding >an electron. Also, there are very few stable positive molecular ions >in the gas phase (if any) with a charge larger than one. They will gain >energy by fragmentation. > >Elementary solution chemistry is full of obviously useful concepts which >nevertheless are incorrect if interpreted literally. > >Rolf Manne >Department of Chemistry, University of Bergen, Norway >e-mail Rolf.Manne@kj.uib.no Actually, multiply charged POSITIVE ions are not uncommon in the gas phase. For example, recent studies with electrospray sources have claimed to prepare ions with >60 charges. DOubly charged negative ions, OTOH, are rare. A couple of examples I can think of are long chain dicarboxylates and buckyball 2-. paul From news-service Wed Apr 21 09:59:36 1993 To: subscribers Newsgroups: sci.chem From: parson_r@cubldr.colorado.edu (Robert Parson) Subject: [News] Re: does sulfate anion SO4(2-) exist? Message-ID: <1993Apr16.133553.1@cubldr.colorado.edu> Nntp-Posting-Host: gold.colorado.edu Organization: University of Colorado, Boulder References: <40506@mch.chem.msu.su> <1993Apr10.134937.26001@kth.se> Date: Fri, 16 Apr 93 20:35:53 GMT Sender: L-usenet@newcom.kiae.su Status: RO In article , nkjrm@alf.uib.no (Rolf Manne) writes: > The original poster raises a valid point. A system like the sulfate > ion without a stabilizing exterior field will gain energy by discarding > an electron. Also, there are very few stable positive molecular ions > in the gas phase (if any) with a charge larger than one. They will gain > energy by fragmentation. > There are some, even small ones: N2++, CO++, quite a few with halogens. They are metastable, but some have very long lifetimes and have been considered as possible high energy density materials. As far as I know there is no unambiguous evidence for doubly charged negative ions in the gas phase. A lot of people are studying cluster ions in order to see in detail how a polar solvent stabilizes the ion, but I don't know if anyone has studied SO4= in water clusters. -- Robert From news-service Wed Apr 21 09:59:36 1993 To: subscribers Newsgroups: sci.chem From: ggawboy@magnus.acs.ohio-state.edu (Galen F Gawboy) Subject: [News] Re: does sulfate anion SO4(2-) exist? Message-ID: <1993Apr16.223401.10957@magnus.acs.ohio-state.edu> Nntp-Posting-Host: bottom.magnus.acs.ohio-state.edu Organization: The Ohio State University References: <40506@mch.chem.msu.su> Date: Fri, 16 Apr 93 22:34:01 GMT Sender: L-usenet@newcom.kiae.su Status: RO >>In article <40506@mch.chem.msu.su>, RUDNYI@mch.chem.msu.su (Rudnyi Evgenii) writes: >>>I study inorganic negative ions in the gas phase and I like thinking on >>>comparing the properties of pure ions and ions in the condensed phases. >>>As for me, the main feature here is the absence of multi-charged anions >>>in the gas phase. > >>>I'm not aware of any reliable observation of multi-charge negative ions >>>in the gas phase at all. Apparently, multi-charge negative ions are >>>unstable in the gas phase and it seems to be tacit agreement among >>>chemists on that. This brings to a question what multi-charge negative >>>ions in the condensed phases are - just a fiction or a reality. > C60(-2) has been observed in the gas phase. An elegant double resonance experiment was done to verify that the carrier of the of the m/z peak of 360 was in fact C60(-2) and not C30-. Galen .sigs are for management stoolies. From news-service Wed Apr 21 09:59:36 1993 To: subscribers From: lmh@juliet.caltech.edu (Henling, Lawrence M.) Newsgroups: sci.chem Subject: [News] Re: does sulfate anion SO4(2-) exist? Date: Fri, 16 Apr 93 22:33:00 -0700 Organization: California Institute of Technology Distribution: world Message-ID: <16APR199322331842@juliet.caltech.edu> References: <1993Apr10.134937.26001@kth.se> <42211@mch.chem.msu.su> NNTP-Posting-Host: juliet.caltech.edu News-Software: VAX/VMS VNEWS 1.41 Sender: L-usenet@newcom.kiae.su Status: RO In article <42211@mch.chem.msu.su>, RUDNYI@mch.chem.msu.su writes... >What entities will you find in that gaseous state? Individual molecules >K2SO4 and dissociation products O2, K and SO2 in about the same >concentrations. How do we know that? By means of mass spectrometry, >which brings straightforward and unambiguous results. How do you use mass spectrometry to measure neutral species? Do you have two sets of deflection plates and ionize the sample not affected by the first one? larry henling lmh@shakes.caltech.edu From news-service Wed Apr 21 09:59:36 1993 To: subscribers From: tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson) Newsgroups: sci.chem Subject: [News] Re: does sulfate anion SO4(2-) exist? Message-ID: <1993Apr17.161108.23362@kth.se> Date: Sat, 17 Apr 93 16:11:08 GMT References: <40506@mch.chem.msu.su> <1993Apr10.134937.26001@kth.se>, Reply-To: tomas_e@LINK.Physchem.KTH.SE Organization: Royal Institute of Technology, Stockholm Nntp-Posting-Host: link.physchem.kth.se Sender: L-usenet@newcom.kiae.su Status: RO In article , nkjrm@alf.uib.no (Rolf Manne) writes: ...About the existence of SO_{4}^{2-} in condensed phases (e.g. solution), called into question by the stated nonexistence of multivalent negative ions in the gas phase... >The original poster raises a valid point. A system like the sulfate >ion without a stabilizing exterior field will gain energy by discarding ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >an electron. Was there ever a *condensed phase* without exterior fields? >Also, there are very few stable positive molecular ions >in the gas phase (if any) with a charge larger than one. They will gain >energy by fragmentation. > >Elementary solution chemistry is full of obviously useful concepts which >nevertheless are incorrect if interpreted literally. What do you mean by this? Is the dissociation of salts into ions in solution just a useful concept, which is actually wrong??? The sulfate ion (and other multivalent negative ions) does not exist in solution??? Tomas Eriksson (tomas_e@physchem.kth.se) Dept. Physical Chemistry, Royal Institute of Technology, Stockholm, Sweden From news-service Wed Apr 21 09:59:36 1993 To: subscribers From: tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson) Newsgroups: sci.chem Subject: [News] Re: does sulfate anion SO4(2-) exist? Message-ID: <1993Apr17.163212.23792@kth.se> Date: Sat, 17 Apr 93 16:32:12 GMT References: <1993Apr10.134937.26001@kth.se>,<42211@mch.chem.msu.su> Reply-To: tomas_e@LINK.Physchem.KTH.SE Organization: Royal Institute of Technology, Stockholm Nntp-Posting-Host: link.physchem.kth.se Sender: L-usenet@newcom.kiae.su Status: RO In article <42211@mch.chem.msu.su>, RUDNYI@mch.chem.msu.su (Rudnyi Evgenii) writes: >FD (field desorption) >SIMS (secondary ion mass spectrometry) >FAB (fast atom bombardment) >LD (laser desorption) >field desorption from solution at atmospheric pressure. > >All these methods claim that they get ions right from the condensed >phase (solid or liquid). This is not obvious though, for secondary >processes are always possible. Nonetheless, all of these methods show >the one-charged ions listed above and no SO4(2-). I recognize a few of the methods you list above, and as far as I can tell, they all do their detection in the gas phase (preferably vacuum). That means that a lot of things can (will) have happened to your ions -- going from a condensed phase to a gaseous state is a rather "traumatic" experience for a poor little ion (losing your neighbours, including any hydration shell, and all that (-: ). From my chemical intuition, unimolecular processes (and fractionating SO_{4}^{2-} to e.g. SO_{2}^{-} and O_{2}^{-}, if that is what occurs, can very well be a unimolecular process) in the gas phase are *very* fast, i.e. measuring anything else than equilibrium composition is very difficult, even if the ions were in a condensed phase a millisecond (or a microsecond) earlier. Or am I wrong? >What we definitely can say from there? The *isolated* double-charged >anion SO4(2-) is unstable, i.e. it throws away the second electron >instantly, forming SO4-. By the way, all theoretical calculations >confirm that. Being an experimentalist, I claim that experience shows that (bad) theoretical calculations can be made to show just anything the theoretician prefers them to show... :-) But truly *isolated* sulfate ions do not exist in a condensed phase. *Nothing* is really isolated in a condensed phase. It may be approximately isolated from a certain species (in low concentration) etc., but what actually separates condensed phases from the gaseous state is that there are a lot of neighbouring molecules everywhere around each molecule... (as I guess you all knew). >>Does this journal >(Izv. Vyssh. Uchebn. Zaved., Khim. Khim. Tekhnol. 1989, v.32, N 5, p.3-12. >where I wrote all mentioned above) >>exist in English translation? > >No, I'm sorry. > >I don't know what all this may imply for solutions and that was my >question. I think that this does not imply anything for solutions. As I wrote in my initial reply to you, there is a lot of (as far I can tell) unambiguous experimental evidence for multivalent anions in solution, based on in-solution-only properties (which makes these measurements different from gas-phase-produced-from-solutions properties, which you seem to quote). I'm not sure if there was ever any serious disagreement about multivalent ions in solution once the dissociation theory (dated approximately 1887) had won acceptance. Tomas Eriksson (tomas_e@physchem.kth.se) Dept. Physical Chemistry, Royal Institute of Technology, Stockholm, Sweden From news-service Thu Apr 22 17:29:47 1993 To: subscribers Newsgroups: sci.chem From: nkjrm@alf.uib.no (ROLF MANNE) Subject: [News] Re: does sulfate anion SO4(2-) exist? Message-ID: Organization: University of Bergen References: <40506@mch.chem.msu.su> <1993Apr10.134937.26001@kth.se>, <1993Apr17.161108.23362@kth.se> Date: Mon, 19 Apr 93 14:20:57 GMT Sender: L-usenet@newcom.kiae.su Status: RO In article <1993Apr17.161108.23362@kth.se> tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson) writes: >In article , nkjrm@alf.uib.no (Rolf Manne) writes: >...About the existence of SO_{4}^{2-} in condensed phases (e.g. solution), >called into question by the stated nonexistence of multivalent negative >ions in the gas phase... >>The original poster raises a valid point. A system like the sulfate >>ion without a stabilizing exterior field will gain energy by discarding > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >>an electron. >Was there ever a *condensed phase* without exterior fields? Of course not. At the same time, it is impossible to define unambiguously where one molecule ends and the next one starts. Therefore, there is no really safe way for counting electrons in the condensed phase. For an isolated molecule/ion in the gas-phase, however, you can count the electrons. >>Also, there are very few stable positive molecular ions >>in the gas phase (if any) with a charge larger than one. They will gain >>energy by fragmentation. >> >>Elementary solution chemistry is full of obviously useful concepts which >>nevertheless are incorrect if interpreted literally. >What do you mean by this? Is the dissociation of salts into ions in >solution just a useful concept, which is actually wrong??? The sulfate >ion (and other multivalent negative ions) does not exist in solution??? Let me take an example: Aluminum, which in many elementary texts occurs as Al3+. The stoichiometry of, e.g. AlCl3, both in solid and in solution makes it natural to write Al3+. The energy required to remove 3 electrons from an Al-atom placing them at infinity is much too large to be of chemical interest. My Swedish high-school chemistry book 40 years ago treated the hydration of aluminum ions in some detail. The triple-positive ion gets surrounded by water molecules leading to a distribution of the positive charge, and in the end a certain acidity. Current general-chemistry textbooks seem to be less careful. Rolf Manne Department of Chemistry, University of Bergen, Norway e-mail: Rolf.Manne@kj.uib.no From news-service Thu Apr 22 17:29:56 1993 To: subscribers Newsgroups: sci.chem From: tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson) Subject: [News] Re: does sulfate anion SO4(2-) exist? Message-ID: <1993Apr20.135057.7926@kth.se> Nntp-Posting-Host: link.physchem.kth.se Reply-To: tomas_e@LINK.Physchem.KTH.SE Organization: Royal Institute of Technology, Stockholm References: <40506@mch.chem.msu.su> <1993Apr10.134937.26001@kth.se>, <1993Apr17.161108.23362@kth.se>, Date: Tue, 20 Apr 93 13:50:57 GMT Sender: L-usenet@newcom.kiae.su Status: RO In article , nkjrm@alf.uib.no (ROLF MANNE) writes: >...At the same time, it is impossible to define unambiguously ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >where one molecule ends and the next one starts. Therefore, there is no ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >really safe way for counting electrons in the condensed phase. >For an isolated molecule/ion in the gas-phase, however, you can count >the electrons. Are you sure you're not a physicist? :-) If we restrict ourself to aqueous solutions (as opposed to e.g. metals in the condensed state), I don't see this as a big problem, and I don't think this is really relevant to our original poster's ponderings. I see no reason whatsoever, based on what has been written in this discussion, to call into question the existence of multivalent anions (e.g. SO_{4}^{2-}) in aqueous solution. I'm still willing to be proven wrong, of course. Tomas Eriksson (tomas_e@physchem.kth.se) Dept. Physical Chemistry, Royal Institute of Technology, Stockholm, Sweden From RUDNYI Tue Apr 27 17:30:22 MSD 1993 To: newsserv@newcom.kiae.su Newsgroups: sci.chem References: <1993Apr17.163212.23792@kth.se> Message-Id: From: RUDNYI@mch.chem.msu.su (Rudnyi Evgenii) Date: Tue, 27 Apr 93 17:30:21 +0400 (MSD) Subject: Re: does sulfate anion SO4(2-) exist? Distribution: world Status: RO I'll begin from answering small questions to my previous messages. me: >I'm not aware of any reliable observation of multi-charge negative ions >in the gas phase at all. ggawboy@magnus.acs.ohio-state.edu (Galen F Gawboy) <1993Apr16.223401.10957@magnus.acs.ohio-state.edu> >C60(-2) has been observed in the gas phase. Yes! I meant only relatively small inorganic ions. Actually I have a few other references for huge negative multi-charged organic molecules in the gas phase. me: >What entities will you find in that gaseous state? Individual molecules >K2SO4 and dissociation products O2, K and SO2 in about the same >concentrations. How do we know that? By means of mass spectrometry. lmh@juliet.caltech.edu (Henling, Lawrence M.) <16APR199322331842@juliet.caltech.edu> >How do you use mass spectrometry to measure neutral species? To this end, neutral molecules were ionized by the electron bombardment. me: >... methods claim that they get ions right from the condensed >phase (solid or liquid). This is not obvious though, for secondary >processes are always possible. Nonetheless, all of these methods show >the one-charged ions ... and no SO4(2-). tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson) <1993Apr17.163212.23792@kth.se> >That means that a lot of things can (will) have happened to your ions -- >going from a condensed phase to a gaseous state is a rather "traumatic" >experience for a poor little ion (losing your neighbours, including any >hydration shell, and all that (-: ). Yes, it does not mean that there is no SO4(2-) in the condensed phase. It just shows that isolated SO4(2-) is unstable as compared with SO4- and a free electron. tomas_e@LINK.Physchem.KTH.SE (Tomas Eriksson) <1993Apr17.163212.23792@kth.se> has finished his message by >I think that this does not imply anything for solutions. As I wrote in >my initial reply to you, there is a lot of (as far I can tell) unambiguous >experimental evidence for multivalent anions in solution, based on >in-solution-only properties (which makes these measurements different >from gas-phase-produced-from-solutions properties, which you seem to >quote). I'm not sure if there was ever any serious disagreement about >multivalent ions in solution once the dissociation theory (dated >approximately 1887) had won acceptance. I don't know much about solution experiments, I'm sorry. I just began once to read about sulfate anion but I found two surprises. First, in the early days (first half of the nineteenth century), sulfate anion was *one-charged* because of the wrong atomic weight for potassium (it was twice more and they wrote potassium sulfate as KSO4). Second, in the original works of Van't Hoff the factor i for K2SO4 which should stay for the number of ions producing from the salt was about two (1.97-2.11) (he sould have used more dilute solutions, I guess). What I don't understand from the modern point of view is (it seems a crazy question but nonetheless) why we can not use fraction numbers for charge of ions in solution chemistry {e.g. SO4(1.5-)}. It seems to me that it would be interesting to take *in-solution-only property* for potassium sulfate and to process them under hypothesis of fraction charges of ions. Shall we obtain the only integers indeed? (-: Evgenii Rudnyi Chemistry Department Moscow State University