K2S + 2HI → 2KI + H2S
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The reaction of potassium sulfide and hydrogen iodide yields potassium iodide and hydrogen sulfide. This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Reaction of potassium sulfide 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 potassium sulfide and hydrogen iodide
Reactants
Chemical formula | Name | Coefficient | Type | Type in general equation |
---|---|---|---|---|
K2S | Potassium sulfide | 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 |
---|---|---|---|---|
KI | Potassium iodide | 2 | Conjugate base | Salt of strong acid |
H2S | Hydrogen sulfide | 1 | Conjugate acid | Weak acid |
Thermodynamic changes
Changes in standard condition
- Reaction of potassium sulfide and hydrogen iodide◆
ΔrG −322.7 kJ/mol K 3.42 × 1056 pK −56.53
Standard enthalpy of reaction ΔrH° kJ · mol−1 | Standard Gibbs energy of reaction ΔrG° kJ · mol−1 | Standard entropy of reaction ΔrS° J · K−1 · mol−1 | Standard heat capacity of reaction at constant pressure ΔrCp° J · K−1 · mol−1 | |
---|---|---|---|---|
per 1 mol of Equation | −348.7 | −322.7 | −100 | – |
per 1 mol of | −348.7 | −322.7 | −100 | – |
per 1 mol of | −174.3 | −161.3 | −50.0 | – |
per 1 mol of | −174.3 | −161.3 | −50.0 | – |
per 1 mol of | −348.7 | −322.7 | −100 | – |
Changes in aqueous solution (1)
- Reaction of potassium sulfide and hydrogen iodide◆
ΔrG −119.4 kJ/mol K 8.28 × 1020 pK −20.92
Standard enthalpy of reaction ΔrH° kJ · mol−1 | Standard Gibbs energy of reaction ΔrG° kJ · mol−1 | Standard entropy of reaction ΔrS° J · K−1 · mol−1 | Standard heat capacity of reaction at constant pressure ΔrCp° J · K−1 · mol−1 | |
---|---|---|---|---|
per 1 mol of Equation | −53.9 | −119.4 | 220.4 | – |
per 1 mol of | −53.9 | −119.4 | 220.4 | – |
per 1 mol of | −26.9 | −59.70 | 110.2 | – |
per 1 mol of | −26.9 | −59.70 | 110.2 | – |
per 1 mol of | −53.9 | −119.4 | 220.4 | – |
Changes in aqueous solution (2)
- Reaction of potassium sulfide and hydrogen iodide◆
ΔrG −113.7 kJ/mol K 8.31 × 1019 pK −19.92
Standard enthalpy of reaction ΔrH° kJ · mol−1 | Standard Gibbs energy of reaction ΔrG° kJ · mol−1 | Standard entropy of reaction ΔrS° J · K−1 · mol−1 | Standard heat capacity of reaction at constant pressure ΔrCp° J · K−1 · mol−1 | |
---|---|---|---|---|
per 1 mol of Equation | −73.0 | −113.7 | 136 | – |
per 1 mol of | −73.0 | −113.7 | 136 | – |
per 1 mol of | −36.5 | −56.85 | 68.0 | – |
per 1 mol of | −36.5 | −56.85 | 68.0 | – |
per 1 mol of | −73.0 | −113.7 | 136 | – |
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 |
---|---|---|---|---|
K2S (cr) | -380.7[1] | -364.0[1] | 105[1] | – |
K2S (ai) | -471.5[1] | -480.7[1] | 190.4[1] | – |
K2S (cr) 2 hydrate | -975.3[1] | – | – | – |
K2S (cr) 5 hydrate | -1871.5[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] |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (g):Gas
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 |
---|---|---|---|---|
KI (cr) | -327.900[1] | -324.892[1] | 106.32[1] | 52.93[1] |
KI (g) | -125.5[1] | -166.1[1] | 258.3[1] | 37.11[1] |
KI (ai) | -307.57[1] | -334.85[1] | 213.8[1] | -120.5[1] |
H2S (g) | -20.63[1] | -33.56[1] | 205.79[1] | 34.23[1] |
H2S (ao) | -39.7[1] | -27.83[1] | 121[1] | – |
* (cr):Crystalline solid, (g):Gas, (ai):Ionized aqueous solution, (ao):Un-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°, -380.7 kJ · mol−1
- ^ ΔfG°, -364.0 kJ · mol−1
- ^ S°, 105. J · K−1 · mol−1
- ^ ΔfH°, -471.5 kJ · mol−1
- ^ ΔfG°, -480.7 kJ · mol−1
- ^ S°, 190.4 J · K−1 · mol−1
- ^ ΔfH°, -975.3 kJ · mol−1
- ^ ΔfH°, -1871.5 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°, -327.900 kJ · mol−1
- ^ ΔfG°, -324.892 kJ · mol−1
- ^ S°, 106.32 J · K−1 · mol−1
- ^ Cp°, 52.93 J · K−1 · mol−1
- ^ ΔfH°, -125.5 kJ · mol−1
- ^ ΔfG°, -166.1 kJ · mol−1
- ^ S°, 258.3 J · K−1 · mol−1
- ^ Cp°, 37.11 J · K−1 · mol−1
- ^ ΔfH°, -307.57 kJ · mol−1
- ^ ΔfG°, -334.85 kJ · mol−1
- ^ S°, 213.8 J · K−1 · mol−1
- ^ Cp°, -120.5 J · K−1 · mol−1
- ^ ΔfH°, -20.63 kJ · mol−1
- ^ ΔfG°, -33.56 kJ · mol−1
- ^ S°, 205.79 J · K−1 · mol−1
- ^ Cp°, 34.23 J · K−1 · mol−1
- ^ ΔfH°, -39.7 kJ · mol−1
- ^ ΔfG°, -27.83 kJ · mol−1
- ^ S°, 121. J · K−1 · mol−1