K3[Fe(CN)6] + 6HBr → 3KBr + FeBr3 + 6HCN
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The reaction of potassium hexacyanidoferrate(III) and hydrogen bromide yields potassium bromide, iron(III) bromide, and hydrogen cyanide. This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Reaction of potassium hexacyanidoferrate(III) and hydrogen bromide
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 hexacyanidoferrate(III) and hydrogen bromide
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K3[Fe(CN)6] | Potassium hexacyanidoferrate(III) | 1 | Brønsted base | Salt of weak acid |
| HBr | Hydrogen bromide | 6 | Brønsted acid | Strong acid |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KBr | Potassium bromide | 3 | Conjugate base | Salt of strong acid |
| FeBr3 | Iron(III) bromide | 1 | Conjugate base | Salt of strong acid |
| HCN | Hydrogen cyanide | 6 | Conjugate acid | Weak acid |
Thermodynamic changes
Changes in standard condition
- Reaction of potassium hexacyanidoferrate(III) and hydrogen bromide
| 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 | −328.2 | – | – | – |
per 1 mol of | −328.2 | – | – | – |
per 1 mol of | −54.70 | – | – | – |
per 1 mol of | −109.4 | – | – | – |
per 1 mol of | −328.2 | – | – | – |
per 1 mol of | −54.70 | – | – | – |
Changes in aqueous solution (1)
- Reaction of potassium hexacyanidoferrate(III) and hydrogen bromide◆
ΔrG −16.0 kJ/mol K 6.35 × 102 pK −2.80 - K3[Fe(CN)6]Ionized aqueous solution + 6HBrIonized aqueous solution3KBrIonized aqueous solution + FeBr3Ionized aqueous solution + 6HCNUn-ionized aqueous solution⟶
| 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 | 32.1 | −16.0 | 162.1 | – |
per 1 mol of | 32.1 | −16.0 | 162.1 | – |
per 1 mol of | 5.35 | −2.67 | 27.02 | – |
per 1 mol of | 10.7 | −5.33 | 54.03 | – |
per 1 mol of | 32.1 | −16.0 | 162.1 | – |
per 1 mol of | 5.35 | −2.67 | 27.02 | – |
Changes in aqueous solution (2)
- Reaction of potassium hexacyanidoferrate(III) and hydrogen bromide◆
ΔrG 300.2 kJ/mol K 0.26 × 10−52 pK 52.59 - K3[Fe(CN)6]Ionized aqueous solution + 6HBrIonized aqueous solution3KBrIonized aqueous solution + FeBr3Ionized aqueous solution + 6HCNIonized aqueous solution⟶
| 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 | 293.1 | 300.2 | −21.5 | – |
per 1 mol of | 293.1 | 300.2 | −21.5 | – |
per 1 mol of | 48.85 | 50.03 | −3.58 | – |
per 1 mol of | 97.70 | 100.1 | −7.17 | – |
per 1 mol of | 293.1 | 300.2 | −21.5 | – |
per 1 mol of | 48.85 | 50.03 | −3.58 | – |
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 |
|---|---|---|---|---|
| K3[Fe(CN)6] (cr) | -249.8[1] | -129.6[1] | 426.06[1] | – |
| K3[Fe(CN)6] (ai) | -195.4[1] | -120.4[1] | 577.8[1] | – |
| HBr (g) | -36.40[1] | -53.45[1] | 198.695[1] | 29.142[1] |
| HBr (ai) | -121.55[1] | -103.96[1] | 82.4[1] | -141.8[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 |
|---|---|---|---|---|
| KBr (cr) | -393.798[1] | -380.66[1] | 95.90[1] | 52.30[1] |
| KBr (g) | -180.08[1] | -212.96[1] | 250.52[1] | 36.920[1] |
| KBr (ai) | -373.92[1] | -387.23[1] | 184.9[1] | -120.1[1] |
| FeBr3 (cr) | -268.2[1] | – | – | – |
| FeBr3 (g) | -123.8[1] | – | – | – |
| FeBr3 (ai) | -413.4[1] | -316.7[1] | -68.6[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, (g):Gas, (ai):Ionized aqueous solution, (l):Liquid, (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°, -249.8 kJ · mol−1
- ^ ΔfG°, -129.6 kJ · mol−1
- ^ S°, 426.06 J · K−1 · mol−1
- ^ ΔfH°, -195.4 kJ · mol−1
- ^ ΔfG°, -120.4 kJ · mol−1
- ^ S°, 577.8 J · K−1 · mol−1
- ^ ΔfH°, -36.40 kJ · mol−1
- ^ ΔfG°, -53.45 kJ · mol−1
- ^ S°, 198.695 J · K−1 · mol−1
- ^ Cp°, 29.142 J · K−1 · mol−1
- ^ ΔfH°, -121.55 kJ · mol−1
- ^ ΔfG°, -103.96 kJ · mol−1
- ^ S°, 82.4 J · K−1 · mol−1
- ^ Cp°, -141.8 J · K−1 · mol−1
- ^ ΔfH°, -393.798 kJ · mol−1
- ^ ΔfG°, -380.66 kJ · mol−1
- ^ S°, 95.90 J · K−1 · mol−1
- ^ Cp°, 52.30 J · K−1 · mol−1
- ^ ΔfH°, -180.08 kJ · mol−1
- ^ ΔfG°, -212.96 kJ · mol−1
- ^ S°, 250.52 J · K−1 · mol−1
- ^ Cp°, 36.920 J · K−1 · mol−1
- ^ ΔfH°, -373.92 kJ · mol−1
- ^ ΔfG°, -387.23 kJ · mol−1
- ^ S°, 184.9 J · K−1 · mol−1
- ^ Cp°, -120.1 J · K−1 · mol−1
- ^ ΔfH°, -268.2 kJ · mol−1
- ^ ΔfH°, -123.8 kJ · mol−1
- ^ ΔfH°, -413.4 kJ · mol−1
- ^ ΔfG°, -316.7 kJ · mol−1
- ^ S°, -68.6 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