2KHCO3 🔥→ K2CO3 + CO2↑ + H2O
Last updated:
- Decomposition of potassium hydrogencarbonate
Decomposition of potassium hydrogencarbonate yields potassium carbonate, carbon dioxide, and water (Other reactions are here). This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Decomposition of potassium hydrogencarbonate
General equation
- Thermal decomposition without redox
- Thermally decomposable substanceLewis conjugate🔥⟶ ProductLewis acid + ProductLewis base
Oxidation state of each atom
- Decomposition of potassium hydrogencarbonate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KHCO3 | Potassium hydrogencarbonate | 2 | Lewis conjugate | Thermally decomposable |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K2CO3 | Potassium carbonate | 1 | Lewis acid | – |
| CO2 | Carbon dioxide | 1 | Lewis acid | – |
| H2O | Water | 1 | Lewis acid | – |
Thermodynamic changes
Changes in standard condition
- Decomposition of potassium hydrogencarbonate◆
ΔrG 32.0 kJ/mol K 0.25 × 10−5 pK 5.61
| 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 | 96.0 | 32.0 | 208.2 | – |
per 1 mol of | 48.0 | 16.0 | 104.1 | – |
per 1 mol of | 96.0 | 32.0 | 208.2 | – |
per 1 mol of | 96.0 | 32.0 | 208.2 | – |
per 1 mol of | 96.0 | 32.0 | 208.2 | – |
Changes in aqueous solution (1)
- Decomposition of potassium hydrogencarbonate◆
ΔrG 14.23 kJ/mol K 0.32 × 10−2 pK 2.49
| 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 | 27.50 | 14.23 | 44.4 | – |
per 1 mol of | 13.75 | 7.115 | 22.2 | – |
per 1 mol of | 27.50 | 14.23 | 44.4 | – |
per 1 mol of | 27.50 | 14.23 | 44.4 | – |
per 1 mol of | 27.50 | 14.23 | 44.4 | – |
Changes in aqueous solution (2)
- Decomposition of potassium hydrogencarbonate◆
ΔrG 22.61 kJ/mol K 0.11 × 10−3 pK 3.96
| 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 | 7.21 | 22.61 | −51.8 | – |
per 1 mol of | 3.60 | 11.30 | −25.9 | – |
per 1 mol of | 7.21 | 22.61 | −51.8 | – |
per 1 mol of | 7.21 | 22.61 | −51.8 | – |
per 1 mol of | 7.21 | 22.61 | −51.8 | – |
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 |
|---|---|---|---|---|
| KHCO3 (cr) | -963.2[1] | -863.5[1] | 115.5[1] | – |
| KHCO3 (ai) | -944.37[1] | -870.04[1] | 193.7[1] | – |
* (cr):Crystalline solid, (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 |
|---|---|---|---|---|
| K2CO3 (cr) | -1151.02[1] | -1063.5[1] | 155.52[1] | 114.43[1] |
| K2CO3 (ai) | -1181.90[1] | -1094.36[1] | 148.1[1] | – |
| K2CO3 (cr) 1.5 hydrate | -1609.2[1] | -1432.5[1] | 203.3[1] | – |
| CO2 (g) | -393.509[1] | -394.359[1] | 213.74[1] | 37.11[1] |
| CO2 (ao) | -413.80[1] | -385.98[1] | 117.6[1] | – |
| H2O (cr) | – | – | – | – |
| H2O (l) | -285.830[1] | -237.129[1] | 69.91[1] | 75.291[1] |
| H2O (g) | -241.818[1] | -228.572[1] | 188.825[1] | 33.577[1] |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (g):Gas, (ao):Un-ionized aqueous solution, (l):Liquid
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°, -963.2 kJ · mol−1
- ^ ΔfG°, -863.5 kJ · mol−1
- ^ S°, 115.5 J · K−1 · mol−1
- ^ ΔfH°, -944.37 kJ · mol−1
- ^ ΔfG°, -870.04 kJ · mol−1
- ^ S°, 193.7 J · K−1 · mol−1
- ^ ΔfH°, -1151.02 kJ · mol−1
- ^ ΔfG°, -1063.5 kJ · mol−1
- ^ S°, 155.52 J · K−1 · mol−1
- ^ Cp°, 114.43 J · K−1 · mol−1
- ^ ΔfH°, -1181.90 kJ · mol−1
- ^ ΔfG°, -1094.36 kJ · mol−1
- ^ S°, 148.1 J · K−1 · mol−1
- ^ ΔfH°, -1609.2 kJ · mol−1
- ^ ΔfG°, -1432.5 kJ · mol−1
- ^ S°, 203.3 J · K−1 · mol−1
- ^ ΔfH°, -393.509 kJ · mol−1
- ^ ΔfG°, -394.359 kJ · mol−1
- ^ S°, 213.74 J · K−1 · mol−1
- ^ Cp°, 37.11 J · K−1 · mol−1
- ^ ΔfH°, -413.80 kJ · mol−1
- ^ ΔfG°, -385.98 kJ · mol−1
- ^ S°, 117.6 J · K−1 · mol−1
- ^ ΔfH°, -285.830 kJ · mol−1
- ^ ΔfG°, -237.129 kJ · mol−1
- ^ S°, 69.91 J · K−1 · mol−1
- ^ Cp°, 75.291 J · K−1 · mol−1
- ^ ΔfH°, -241.818 kJ · mol−1
- ^ ΔfG°, -228.572 kJ · mol−1
- ^ S°, 188.825 J · K−1 · mol−1
- ^ Cp°, 33.577 J · K−1 · mol−1