The primary goal of this thesis is to analyze geometrical trends of thermodynamic and related functions of low valent sulfur polymer groups in order to determine the thermodynamic properties of these species.
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Abstract
The primary goal of this thesis is to analyze geometrical trends of thermodynamic and related functions of low valent sulfur polymer groups in order to determine the thermodynamic properties of these species.
The following geometries were observed or inferred. a). H22Sn(g,aq, n ≥ 2): analogy with other isostructural molecular polymer groups indicates that all of its thermodynamic properties will be linear functions of n. b). SnS-2 (aq, n ≥ 1): a speciation model is developed that is in agreement witb the best experimental data, which proposes that Δ G°f,n has an inverted gaussian geometry with respect to n with the curve minima being centered at ne. This model is extrapolated to high temperatures. c). Sn(g,n ≥ 2): n-logfstot data appears to have the same geometry at all temperatures and to exhibit iso-n linearity on a logfstot vs. 1/T plot, implying that Cp °n and Δ H°f,n but not S°n or ΔG°f,n are linear functions of n over the temperature range of the data. A multi-temperature speciation model is developed based on the assumption that Sn(g,chains,n = 2-5) and Sn(s,rings, n = 6-8) constitute separate isostructural homologous groups. d). Sm(aq, m > 0): Analysis of the behaviour of polysulfides in various media suggests that Kdm, which governs the scission of SnS-2 to Sm radicals, increases with m.
Secondarily, the isostructural-isovalent non-polymeric O-S-Se-Te(=X) group is discussed in light of Sverjensky's (1984) observations and reactions like logK (H2X,g = HX· + H+) are shown to be linear functions of ΔG°f(H2X,g). These Sverjensky correspondence plots (SCPs) will allow pKa2(H2S) tobe determined from H2Se and H2Te. A restricted isocoulumbic extrapolation technique termed 'twinning', that matches isostructural-isovalent products and reactants, is used to extrapolate some types of data to high temperatures, including ΔG°f(S2O3-2). Tue twinning of 25°C SCPs can generate adundant multi-temperature data.
Table of Contents
Chapter I. The Sulfide Species ... p1
1). Introduction ... pl
2). Henry's Constant, KH ... pl
3). Ka1 ... p2
4). Ka2 ... p6
5). ∑s-2 and Sverjenski Correspondence Plots ... p7
6). The Combination of Twinning with Sverjensky Correspondence
Plots ... p10
7). Conclusions ... p16
Chapter II. The Unprotonated Polysulfid es Nea r Room Temperature
... p19
1). lntroduction ... p19
2). Mathamatical Representation of Polysulfide Equilibria ... p20
3). Experimental Data and Speciation Models ... p22
3a). Be, ne and n.. ... p23
3b). Speciation ModeJs ... p26
4). Symmetry Considerations ... p29
4a). ΔG°f,n vs. n ... p29
4b). Constructing the Model ... ... p29
5.) Conclusions ... p36
Chapter III. Hydrogen Polysulfides (H2SSn,g,aq) ... p37
1). lntroduction ... p37
2). The Homologous Group Approach ... p37
3). H2SSn,g ... p40
4 ). H2SSn,aq ... p42
Chapter IV. Elemental Sulfur ... p46
1). Introduction ... p46
2). Sn,g ... p46
2a). Introduction ... p47
2b). Representation of Equilibria ... p47
3). Experimental Data on Sn,g ... p48
3a). Saturated Vapor Pressure ... p48
3b). n-fstote ... p48
3c). Analysis of n-log(fstote) Data ... p57
4). Sn,g Speciation Models ... p59
4a). Previous Work ... p59
4b). New Model ... p62
4c). Comparison of Models ... p64
4d). Conclusions ... p69
Chapter V. The Hypersulfides (Sm) ... p70
1). Introduction ... p70
2). S3 ... p72
3). S2 ... p72
4). S4 ... p73
S). S1 ... p74
6). Graphical Representation of Equilibria ... p74
6a). un and um ... p75
6b ). un,t and um-,t ... p76
7). The Interpertation of Published Spectra ... p78
7a).Dubois, Lelieur and Lepoutre's Studies ... p78
7b ). Kdm trends ... p85
7c). Other Studies ... p86
8). Conclusions ... p89
Chapter VI. High Temperature Equilibria ... p90
1). Introduction ... p90
2). The Polysulfides ... p90
3). The Hypersulfides ... p96
4). Disproportionation of Elemental Sulfur ... p105
4a). Basic Solutions ... p105
4b). Acidic Solutions ... p106
5). Free Energy of S203-2
... p108
5a). Giggenbach (1974a) ... p108
5b). Uyama, Chiba, Kusakabe and Sakai (1985a,b) ... p109
5c). Mel, Hugus and Latimer (1956) ... p113
6). Inter-Species Relationships ... p114
7). Conclusions ... p121
Chapter VII. Comments on Applied S-H20 Chemistry ... p 122
References ... p129
Frequently asked questions
What is the main topic of this document?
The primary goal of this thesis is to analyze geometrical trends of thermodynamic and related functions of low valent sulfur polymer groups in order to determine the thermodynamic properties of these species.
What geometries are discussed in the abstract?
The abstract mentions the following geometries:
- H2Sn(g,aq, n ≥ 2)
- SnS-2 (aq, n ≥ 1)
- Sn(g,n ≥ 2)
- Sm(aq, m > 0)
What does the abstract say about Sverjensky Correspondence Plots (SCPs)?
The abstract states that Sverjensky correspondence plots (SCPs) will allow pKa2(H2S) to be determined from H2Se and H2Te, and that the twinning of 25°C SCPs can generate abundant multi-temperature data.
What are the chapters in this document?
The document consists of the following chapters:
- Chapter I. The Sulfide Species
- Chapter II. The Unprotonated Polysulfides Near Room Temperature
- Chapter III. Hydrogen Polysulfides (H2SSn,g,aq)
- Chapter IV. Elemental Sulfur
- Chapter V. The Hypersulfides (Sm)
- Chapter VI. High Temperature Equilibria
- Chapter VII. Comments on Applied S-H20 Chemistry
What are the topics discussed in Chapter I, "The Sulfide Species"?
Chapter I covers the following topics:
- Introduction
- Henry's Constant, KH
- Ka1
- Ka2
- ∑s-2 and Sverjenski Correspondence Plots
- The Combination of Twinning with Sverjensky Correspondence Plots
- Conclusions
What are the topics discussed in Chapter II, "The Unprotonated Polysulfides Near Room Temperature"?
Chapter II discusses the following topics:
- Introduction
- Mathematical Representation of Polysulfide Equilibria
- Experimental Data and Speciation Models
- Symmetry Considerations
- Conclusions
What topics are included in Chapter III, "Hydrogen Polysulfides (H2SSn,g,aq)"?
Chapter III includes:
- Introduction
- The Homologous Group Approach
- H2SSn,g
- H2SSn,aq
What topics are discussed in Chapter IV, "Elemental Sulfur"?
Chapter IV covers:
- Introduction
- Sn,g
- Experimental Data on Sn,g
- Sn,g Speciation Models
- Conclusions
What are the main topics of Chapter V, "The Hypersulfides (Sm)"?
Chapter V explores:
- Introduction
- S3
- S2
- S4
- S1
- Graphical Representation of Equilibria
- The Interpretation of Published Spectra
- Conclusions
What topics are covered in Chapter VI, "High Temperature Equilibria"?
Chapter VI discusses:
- Introduction
- The Polysulfides
- The Hypersulfides
- Disproportionation of Elemental Sulfur
- Free Energy of S203-2
- Inter-Species Relationships
- Conclusions
What is the topic of Chapter VII?
Chapter VII provides "Comments on Applied S-H20 Chemistry".
- Citar trabajo
- Edward Hamilton (Autor), 1991, The Chemistry of Low Valent Sulfur Compounds in the S-H2O System, Múnich, GRIN Verlag, https://www.grin.com/document/318809
