(NH4)2S2O3 + 2HI → 2NH4I + H2S2O3
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The reaction of ammonium thiosulfate and hydrogen iodide yields ammonium iodide and thiosulfuric acid. This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Reaction of ammonium thiosulfate and hydrogen iodide
General equation
- Salt of weak acidBrønsted base + Strong acidBrønsted acid ⟶ Salt of strong acidConjugate base + Weak acidConjugate acid
Oxidation state of each atom
- Reaction of ammonium thiosulfate and hydrogen iodide
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| (NH4)2S2O3 | Ammonium thiosulfate | 1 | Brønsted base | Salt of weak acid |
| HI | Hydrogen iodide | 2 | Brønsted acid | Strong acid |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| NH4I | Ammonium iodide | 2 | Conjugate base | Salt of strong acid |
| H2S2O3 | Thiosulfuric acid | 1 | Conjugate acid | Weak acid |
Thermodynamic changes
Thermodynamic data of reactants
| Chemical formula | Standard enthalpy of formation ΔfH° kJ · mol−1 | Standard Gibbs energy of formation ΔfG° kJ · mol−1 | Standard molar entropy S° J · K−1 · mol−1 | Standard molar heat capacity at constant pressure Cp° J · K−1 · mol−1 |
|---|---|---|---|---|
| (NH4)2S2O3 (aq) | -917.1[1] | – | – | – |
| HI (g) | 26.48[1] | 1.70[1] | 206.594[1] | 29.158[1] |
| HI (ai) | -55.19[1] | -51.57[1] | 111.3[1] | -142.3[1] |
* (aq):Aqueous solution, (g):Gas, (ai):Ionized aqueous solution
Thermodynamic data of products
| Chemical formula | Standard enthalpy of formation ΔfH° kJ · mol−1 | Standard Gibbs energy of formation ΔfG° kJ · mol−1 | Standard molar entropy S° J · K−1 · mol−1 | Standard molar heat capacity at constant pressure Cp° J · K−1 · mol−1 |
|---|---|---|---|---|
| NH4I (cr) | -201.42[1] | -112.5[1] | 117[1] | – |
| NH4I (ai) | -187.69[1] | -130.88[1] | 224.7[1] | -62.3[1] |
| H2S2O3 | – | – | – | – |
* (cr):Crystalline solid, (ai):Ionized aqueous solution
References
List of references
- 1Janiel J. Reed (1989)The NBS Tables of Chemical Thermodynamic Properties: Selected Values for Inorganic and C1 and C2 Organic Substances in SI UnitsNational Institute of Standards and Technology (NIST)
- ^ ΔfH°, -917.1 kJ · mol−1
- ^ ΔfH°, 26.48 kJ · mol−1
- ^ ΔfG°, 1.70 kJ · mol−1
- ^ S°, 206.594 J · K−1 · mol−1
- ^ Cp°, 29.158 J · K−1 · mol−1
- ^ ΔfH°, -55.19 kJ · mol−1
- ^ ΔfG°, -51.57 kJ · mol−1
- ^ S°, 111.3 J · K−1 · mol−1
- ^ Cp°, -142.3 J · K−1 · mol−1
- ^ ΔfH°, -201.42 kJ · mol−1
- ^ ΔfG°, -112.5 kJ · mol−1
- ^ S°, 117. J · K−1 · mol−1
- ^ ΔfH°, -187.69 kJ · mol−1
- ^ ΔfG°, -130.88 kJ · mol−1
- ^ S°, 224.7 J · K−1 · mol−1
- ^ Cp°, -62.3 J · K−1 · mol−1