2Al(OH)3 🔥→ Al2O3 + 3H2O
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- Decomposition of aluminium hydroxide
Decomposition of aluminium hydroxide yields aluminium oxide and water. This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Decomposition of aluminium hydroxide
General equation
- Thermal decomposition without redox
- Thermally decomposable substanceLewis conjugate🔥⟶ ProductLewis acid + ProductLewis base
- Thermal decomposition of hydroxide
- Hydroxide🔥⟶ OxideConjugate base + H2OConjugate acid
Oxidation state of each atom
- Decomposition of aluminium hydroxide
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Al(OH)3 | Aluminium hydroxide | 2 | Lewis conjugate – | Thermally decomposable Hydroxide |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Al2O3 | Aluminium oxide | 1 | Lewis acid Conjugate base | – Oxide |
| H2O | Water | 3 | Lewis acid Conjugate acid | – Water |
Thermodynamic changes
Changes in standard condition (1)
- Decomposition of aluminium hydroxide◆
ΔrG 318 kJ/mol K 0.19 × 10−55 pK 55.71
| 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 | 35 | 318 | 119 | 118.7 |
per 1 mol of | 18 | 159 | 59.5 | 59.35 |
per 1 mol of | 35 | 318 | 119 | 118.7 |
per 1 mol of | 12 | 106 | 39.7 | 39.57 |
Changes in standard condition (2)
- Decomposition of aluminium hydroxide
| 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 | – | – | – |
per 1 mol of | 22 | – | – | – |
per 1 mol of | 44 | – | – | – |
per 1 mol of | 15 | – | – | – |
Changes in standard condition (3)
- Decomposition of aluminium hydroxide
| 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 | 54 | – | – | – |
per 1 mol of | 27 | – | – | – |
per 1 mol of | 54 | – | – | – |
per 1 mol of | 18 | – | – | – |
Changes in standard condition (4)
- Decomposition of aluminium hydroxide
| 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 | 48 | – | – | – |
per 1 mol of | 24 | – | – | – |
per 1 mol of | 48 | – | – | – |
per 1 mol of | 16 | – | – | – |
Changes in standard condition (5)
- Decomposition of aluminium hydroxide
| 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 | 54 | – | – | – |
per 1 mol of | 27 | – | – | – |
per 1 mol of | 54 | – | – | – |
per 1 mol of | 18 | – | – | – |
Changes in standard condition (6)
- Decomposition of aluminium hydroxide
| 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 | 79 | – | – | – |
per 1 mol of | 40 | – | – | – |
per 1 mol of | 79 | – | – | – |
per 1 mol of | 26 | – | – | – |
Changes in standard condition (7)
- Decomposition of aluminium hydroxide
| 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 | 19 | – | – | – |
per 1 mol of | 9.5 | – | – | – |
per 1 mol of | 19 | – | – | – |
per 1 mol of | 6.3 | – | – | – |
Changes in standard condition (8)
- Decomposition of aluminium hydroxide
| 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 | 28 | – | – | – |
per 1 mol of | 14 | – | – | – |
per 1 mol of | 28 | – | – | – |
per 1 mol of | 9.3 | – | – | – |
Changes in standard condition (9)
- Decomposition of aluminium hydroxide
| 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 | 38 | – | – | – |
per 1 mol of | 19 | – | – | – |
per 1 mol of | 38 | – | – | – |
per 1 mol of | 13 | – | – | – |
Changes in standard condition (10)
- Decomposition of aluminium hydroxide
| 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 | – | – | – |
per 1 mol of | 16 | – | – | – |
per 1 mol of | 32 | – | – | – |
per 1 mol of | 11 | – | – | – |
Changes in standard condition (11)
- Decomposition of aluminium hydroxide
| 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 | 38 | – | – | – |
per 1 mol of | 19 | – | – | – |
per 1 mol of | 38 | – | – | – |
per 1 mol of | 13 | – | – | – |
Changes in standard condition (12)
- Decomposition of aluminium hydroxide
| 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 | 63 | – | – | – |
per 1 mol of | 32 | – | – | – |
per 1 mol of | 63 | – | – | – |
per 1 mol of | 21 | – | – | – |
Changes in aqueous solution
- Decomposition of aluminium hydroxide◆
ΔrG 318 kJ/mol K 0.19 × 10−55 pK 55.71
| 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 | 35 | 318 | 119 | 118.7 |
per 1 mol of | 18 | 159 | 59.5 | 59.35 |
per 1 mol of | 35 | 318 | 119 | 118.7 |
per 1 mol of | 12 | 106 | 39.7 | 39.57 |
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 |
|---|---|---|---|---|
| Al(OH)3 (cr) | -1284[1] | -1306[1] | 71[1] | 93.1[1] |
| Al(OH)3 (am) | -1276[2] | – | – | – |
* (cr):Crystalline solid, (am):Amorphous solid
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 |
|---|---|---|---|---|
| Al2O3 (cr) α, corundum | -1675.7[2] | -1582.3[2] | 50.92[2] | 79.04[2] |
| Al2O3 (cr) δ | -1666.5[2] | – | – | – |
| Al2O3 (cr) ρ | -1657[2] | – | – | – |
| Al2O3 (cr) κ | -1662.3[2] | – | – | – |
| Al2O3 (cr) γ | -1656.9[2] | – | – | – |
| Al2O3 (am) | -1632[2] | – | – | – |
| Al2O3 (cr) 1 hydrate | -1998.91[2] | -1841.78[2] | 70.67[2] | 106.19[2] |
| Al2O3 (cr) 3 hydrate | -2576.5[2] | – | – | – |
| H2O (cr) | – | – | – | – |
| H2O (l) | -285.830[2] | -237.129[2] | 69.91[2] | 75.291[2] |
| H2O (g) | -241.818[2] | -228.572[2] | 188.825[2] | 33.577[2] |
* (cr):Crystalline solid, (am):Amorphous solid, (l):Liquid, (g):Gas
References
List of references
- 1James G. Speight (2017)Lange's Handbook of Chemistry, 17th editionMcGraw Hill Education
- ^ ΔfH°, -1284 kJ · mol−1 - p.254
- ^ ΔfG°, -1306 kJ · mol−1 - p.254
- ^ S°, 71 J · K−1 · mol−1 - p.254
- ^ Cp°, 93.1 J · K−1 · mol−1 - p.254
- 2Janiel 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°, -1276. kJ · mol−1
- ^ ΔfH°, -1675.7 kJ · mol−1
- ^ ΔfG°, -1582.3 kJ · mol−1
- ^ S°, 50.92 J · K−1 · mol−1
- ^ Cp°, 79.04 J · K−1 · mol−1
- ^ ΔfH°, -1666.5 kJ · mol−1
- ^ ΔfH°, -1657. kJ · mol−1
- ^ ΔfH°, -1662.3 kJ · mol−1
- ^ ΔfH°, -1656.9 kJ · mol−1
- ^ ΔfH°, -1632. kJ · mol−1
- ^ ΔfH°, -1998.91 kJ · mol−1
- ^ ΔfG°, -1841.78 kJ · mol−1
- ^ S°, 70.67 J · K−1 · mol−1
- ^ Cp°, 106.19 J · K−1 · mol−1
- ^ ΔfH°, -2576.5 kJ · 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