KHS + HSCN 🔥→ KSCN + H2S↑
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The reaction of potassium hydrogensulfide and thiocyanic acid yields potassium thiocyanate 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 hydrogensulfide and thiocyanic acid
General equation
- Salt of volatile acidBrønsted base + Nonvolatile acidBrønsted acid ⟶ Salt of non volatile acidConjugate base + Volatile acidConjugate acid
Oxidation state of each atom
- Reaction of potassium hydrogensulfide and thiocyanic acid
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KHS | Potassium hydrogensulfide | 1 | Brønsted base | Salt of volatile acid |
| HSCN | Thiocyanic acid | 1 | Brønsted acid | Nonvolatile acid |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KSCN | Potassium thiocyanate | 1 | Conjugate base | Salt of non volatile acid |
| H2S | Hydrogen sulfide | 1 | Conjugate acid | Volatile acid |
Thermodynamic changes
Changes in aqueous solution (1)
- Reaction of potassium hydrogensulfide and thiocyanic acid◆
ΔrG −45.64 kJ/mol K 9.90 × 107 pK −8.00
| 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 | −3.1 | −45.64 | 143.1 | – |
per 1 mol of | −3.1 | −45.64 | 143.1 | – |
per 1 mol of | −3.1 | −45.64 | 143.1 | – |
per 1 mol of | −3.1 | −45.64 | 143.1 | – |
per 1 mol of | −3.1 | −45.64 | 143.1 | – |
Changes in aqueous solution (2)
- Reaction of potassium hydrogensulfide and thiocyanic acid◆
ΔrG −39.91 kJ/mol K 9.82 × 106 pK −6.99
| 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 | −22.2 | −39.91 | 58 | – |
per 1 mol of | −22.2 | −39.91 | 58 | – |
per 1 mol of | −22.2 | −39.91 | 58 | – |
per 1 mol of | −22.2 | −39.91 | 58 | – |
per 1 mol of | −22.2 | −39.91 | 58 | – |
Changes in aqueous solution (3)
- Reaction of potassium hydrogensulfide and thiocyanic acid◆
ΔrG −50.49 kJ/mol K 7.01 × 108 pK −8.85
| 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 | – | −50.49 | – | – |
per 1 mol of | – | −50.49 | – | – |
per 1 mol of | – | −50.49 | – | – |
per 1 mol of | – | −50.49 | – | – |
per 1 mol of | – | −50.49 | – | – |
Changes in aqueous solution (4)
- Reaction of potassium hydrogensulfide and thiocyanic acid◆
ΔrG −44.76 kJ/mol K 6.94 × 107 pK −7.84
| 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 | – | −44.76 | – | – |
per 1 mol of | – | −44.76 | – | – |
per 1 mol of | – | −44.76 | – | – |
per 1 mol of | – | −44.76 | – | – |
per 1 mol of | – | −44.76 | – | – |
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 |
|---|---|---|---|---|
| KHS (cr) | -265.10[1] | – | – | 75.31[1] |
| KHS (ai) | -269.9[1] | -271.19[1] | 165.3[1] | – |
| KHS (cr) 0.25 hydrate | -337.2[1] | – | – | – |
| HSCN (ai) | 76.44[1] | 92.71[1] | 144.3[1] | -40.2[1] |
| HSCN (ao) | – | 97.56[1] | – | – |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (ao):Un-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 |
|---|---|---|---|---|
| KSCN (cr) | -200.16[1] | -178.31[1] | 124.26[1] | 88.53[1] |
| KSCN (ai) | -175.94[1] | -190.56[1] | 246.9[1] | -18.4[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, (ai):Ionized aqueous solution, (g):Gas, (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°, -265.10 kJ · mol−1
- ^ Cp°, 75.31 J · K−1 · mol−1
- ^ ΔfH°, -269.9 kJ · mol−1
- ^ ΔfG°, -271.19 kJ · mol−1
- ^ S°, 165.3 J · K−1 · mol−1
- ^ ΔfH°, -337.2 kJ · mol−1
- ^ ΔfH°, 76.44 kJ · mol−1
- ^ ΔfG°, 92.71 kJ · mol−1
- ^ S°, 144.3 J · K−1 · mol−1
- ^ Cp°, -40.2 J · K−1 · mol−1
- ^ ΔfG°, 97.56 kJ · mol−1
- ^ ΔfH°, -200.16 kJ · mol−1
- ^ ΔfG°, -178.31 kJ · mol−1
- ^ S°, 124.26 J · K−1 · mol−1
- ^ Cp°, 88.53 J · K−1 · mol−1
- ^ ΔfH°, -175.94 kJ · mol−1
- ^ ΔfG°, -190.56 kJ · mol−1
- ^ S°, 246.9 J · K−1 · mol−1
- ^ Cp°, -18.4 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