KCN + H2SO4 → KHSO4 + HCN
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The reaction of potassium cyanide and sulfuric acid yields potassium hydrogensulfate and hydrogen cyanide (Other reactions are here). This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Reaction of potassium cyanide and sulfuric acid
General equation
- Salt of weak acidBrønsted base + Strong acidBrønsted acid ⟶ Salt of strong acidConjugate base + Weak acidConjugate acid
- 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 cyanide and sulfuric acid
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KCN | Potassium cyanide | 1 | Brønsted base | Salt of weak acid Salt of volatile acid |
| H2SO4 | Sulfuric acid | 1 | Brønsted acid | Strong acid Nonvolatile acid |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KHSO4 | Potassium hydrogensulfate | 1 | Conjugate base | Salt of strong acid Salt of non volatile acid |
| HCN | Hydrogen cyanide | 1 | Conjugate acid | Weak acid Volatile acid |
Thermodynamic changes
Changes in standard condition
- Reaction of potassium cyanide and sulfuric acid◆
ΔrG −114.5 kJ/mol K 1.15 × 1020 pK −20.06
| 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 | −124.7 | −114.5 | −34.5 | – |
per 1 mol of | −124.7 | −114.5 | −34.5 | – |
per 1 mol of | −124.7 | −114.5 | −34.5 | – |
per 1 mol of | −124.7 | −114.5 | −34.5 | – |
per 1 mol of | −124.7 | −114.5 | −34.5 | – |
Changes in aqueous solution (1)
- Reaction of potassium cyanide and sulfuric acid◆
ΔrG −64.1 kJ/mol K 1.70 × 1011 pK −11.23
| 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 | −21.7 | −64.1 | 142.3 | – |
per 1 mol of | −21.7 | −64.1 | 142.3 | – |
per 1 mol of | −21.7 | −64.1 | 142.3 | – |
per 1 mol of | −21.7 | −64.1 | 142.3 | – |
per 1 mol of | −21.7 | −64.1 | 142.3 | – |
Changes in aqueous solution (2)
- Reaction of potassium cyanide and sulfuric acid◆
ΔrG −11.4 kJ/mol K 9.94 × 101 pK −2.00
| 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 | 21.9 | −11.4 | 111.7 | – |
per 1 mol of | 21.9 | −11.4 | 111.7 | – |
per 1 mol of | 21.9 | −11.4 | 111.7 | – |
per 1 mol of | 21.9 | −11.4 | 111.7 | – |
per 1 mol of | 21.9 | −11.4 | 111.7 | – |
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 |
|---|---|---|---|---|
| KCN (cr) | -113.0[1] | -101.86[1] | 128.49[1] | 66.27[1] |
| KCN (g) | 90.8[1] | 64.17[1] | 261.90[1] | 52.34[1] |
| KCN (ai) | -101.7[1] | -110.9[1] | 196.6[1] | – |
| H2SO4 (cr) | – | – | – | – |
| H2SO4 (l) | -813.989[1] | -690.003[1] | 156.904[1] | 138.91[1] |
| H2SO4 (ai) | -909.27[1] | -744.53[1] | 20.1[1] | -293[1] |
| H2SO4 (l) 1 hydrate | -1127.621[1] | -950.383[1] | 211.54[1] | 214.85[1] |
| H2SO4 (l) 2 hydrate | -1427.100[1] | -1199.650[1] | 276.40[1] | 260.83[1] |
| H2SO4 (l) 3 hydrate | -1720.402[1] | -1443.980[1] | 345.39[1] | 318.95[1] |
| H2SO4 (l) 4 hydrate | -2011.199[1] | -1685.863[1] | 414.59[1] | 382.21[1] |
| H2SO4 (l) 6.5 hydrate | -2733.256[1] | -2285.734[1] | 587.89[1] | 570.28[1] |
* (cr):Crystalline solid, (g):Gas, (ai):Ionized aqueous solution, (l):Liquid
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 |
|---|---|---|---|---|
| KHSO4 (cr) | -1160.6[1] | -1031.3[1] | 138.1[1] | – |
| KHSO4 (ai) | -1139.72[1] | -1039.18[1] | 234.3[1] | -63[1] |
| HCN (l) | 108.87[1] | 124.97[1] | 112.84[1] | 70.63[1] |
| HCN (g) | 135.1[1] | 124.7[1] | 201.78[1] | 35.86[1] |
| HCN (ai) | 150.6[1] | 172.4[1] | 94.1[1] | – |
| HCN (ao) | 107.1[1] | 119.7[1] | 124.7[1] | – |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (l):Liquid, (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°, -113.0 kJ · mol−1
- ^ ΔfG°, -101.86 kJ · mol−1
- ^ S°, 128.49 J · K−1 · mol−1
- ^ Cp°, 66.27 J · K−1 · mol−1
- ^ ΔfH°, 90.8 kJ · mol−1
- ^ ΔfG°, 64.17 kJ · mol−1
- ^ S°, 261.90 J · K−1 · mol−1
- ^ Cp°, 52.34 J · K−1 · mol−1
- ^ ΔfH°, -101.7 kJ · mol−1
- ^ ΔfG°, -110.9 kJ · mol−1
- ^ S°, 196.6 J · K−1 · mol−1
- ^ ΔfH°, -813.989 kJ · mol−1
- ^ ΔfG°, -690.003 kJ · mol−1
- ^ S°, 156.904 J · K−1 · mol−1
- ^ Cp°, 138.91 J · K−1 · mol−1
- ^ ΔfH°, -909.27 kJ · mol−1
- ^ ΔfG°, -744.53 kJ · mol−1
- ^ S°, 20.1 J · K−1 · mol−1
- ^ Cp°, -293. J · K−1 · mol−1
- ^ ΔfH°, -1127.621 kJ · mol−1
- ^ ΔfG°, -950.383 kJ · mol−1
- ^ S°, 211.54 J · K−1 · mol−1
- ^ Cp°, 214.85 J · K−1 · mol−1
- ^ ΔfH°, -1427.100 kJ · mol−1
- ^ ΔfG°, -1199.650 kJ · mol−1
- ^ S°, 276.40 J · K−1 · mol−1
- ^ Cp°, 260.83 J · K−1 · mol−1
- ^ ΔfH°, -1720.402 kJ · mol−1
- ^ ΔfG°, -1443.980 kJ · mol−1
- ^ S°, 345.39 J · K−1 · mol−1
- ^ Cp°, 318.95 J · K−1 · mol−1
- ^ ΔfH°, -2011.199 kJ · mol−1
- ^ ΔfG°, -1685.863 kJ · mol−1
- ^ S°, 414.59 J · K−1 · mol−1
- ^ Cp°, 382.21 J · K−1 · mol−1
- ^ ΔfH°, -2733.256 kJ · mol−1
- ^ ΔfG°, -2285.734 kJ · mol−1
- ^ S°, 587.89 J · K−1 · mol−1
- ^ Cp°, 570.28 J · K−1 · mol−1
- ^ ΔfH°, -1160.6 kJ · mol−1
- ^ ΔfG°, -1031.3 kJ · mol−1
- ^ S°, 138.1 J · K−1 · mol−1
- ^ ΔfH°, -1139.72 kJ · mol−1
- ^ ΔfG°, -1039.18 kJ · mol−1
- ^ S°, 234.3 J · K−1 · mol−1
- ^ Cp°, -63. J · K−1 · mol−1
- ^ ΔfH°, 108.87 kJ · mol−1
- ^ ΔfG°, 124.97 kJ · mol−1
- ^ S°, 112.84 J · K−1 · mol−1
- ^ Cp°, 70.63 J · K−1 · mol−1
- ^ ΔfH°, 135.1 kJ · mol−1
- ^ ΔfG°, 124.7 kJ · mol−1
- ^ S°, 201.78 J · K−1 · mol−1
- ^ Cp°, 35.86 J · K−1 · mol−1
- ^ ΔfH°, 150.6 kJ · mol−1
- ^ ΔfG°, 172.4 kJ · mol−1
- ^ S°, 94.1 J · K−1 · mol−1
- ^ ΔfH°, 107.1 kJ · mol−1
- ^ ΔfG°, 119.7 kJ · mol−1
- ^ S°, 124.7 J · K−1 · mol−1