3HClO3 🔥|🕒→ HClO4 + 2ClO2↑ + H2O
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- Decomposition of chloric acid
Decomposition of chloric acid yields perchloric acid, chlorine dioxide, and water (Other reactions are here). This reaction is an oxidation-reduction reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Decomposition of chloric acid
General equation
- Thermal decomposition with redox
- Thermally decomposable substanceSelf redox agent🔥⟶ ProductOxidation product + ProductReduction product
- Spontaneous decomposition with redox
- Spontaneously decomposable substanceSelf redox agent🕒⟶ ProductOxidation product + ProductReduction product
Oxidation state of each atom
- Decomposition of chloric acid
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| HClO3 | Chloric acid | 3 | – | Thermally decomposable Spontaneously decomposable |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| HClO4 | Perchloric acid | 1 | Oxidized | – |
| ClO2 | Chlorine dioxide | 2 | Reduced | – |
| H2O | Water | 1 | – | – |
Thermodynamic changes
Changes in standard condition (1)
- Decomposition of chloric acid◆
ΔrG 19.2 kJ/mol K 0.43 × 10−3 pK 3.36
| 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 | 101.8 | 19.2 | 278.7 | – |
per 1 mol of | 33.93 | 6.40 | 92.90 | – |
per 1 mol of | 101.8 | 19.2 | 278.7 | – |
per 1 mol of | 50.90 | 9.60 | 139.3 | – |
per 1 mol of | 101.8 | 19.2 | 278.7 | – |
Changes in standard condition (2)
- Decomposition of chloric acid◆
ΔrG 18.4 kJ/mol K 0.60 × 10−3 pK 3.22
| 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 | 46.6 | 18.4 | 94.6 | – |
per 1 mol of | 15.5 | 6.13 | 31.5 | – |
per 1 mol of | 46.6 | 18.4 | 94.6 | – |
per 1 mol of | 23.3 | 9.20 | 47.3 | – |
per 1 mol of | 46.6 | 18.4 | 94.6 | – |
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 |
|---|---|---|---|---|
| HClO3 (ai) | -103.97[1] | -7.95[1] | 162.3[1] | – |
* (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 |
|---|---|---|---|---|
| HClO4 (l) | -40.58[1] | – | – | – |
| HClO4 (ai) | -129.33[1] | -8.52[1] | 182.0[1] | – |
| HClO4 (cr) 1 hydrate | -382.21[1] | – | – | – |
| HClO4 (l) 2 hydrate | -677.98[1] | – | – | – |
| ClO2 (g) | 102.5[1] | 120.5[1] | 256.84[1] | 41.97[1] |
| ClO2 (ao) | 74.9[1] | 120.1[1] | 164.8[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] |
* (l):Liquid, (ai):Ionized aqueous solution, (cr):Crystalline solid, (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°, -103.97 kJ · mol−1
- ^ ΔfG°, -7.95 kJ · mol−1
- ^ S°, 162.3 J · K−1 · mol−1
- ^ ΔfH°, -40.58 kJ · mol−1
- ^ ΔfH°, -129.33 kJ · mol−1
- ^ ΔfG°, -8.52 kJ · mol−1
- ^ S°, 182.0 J · K−1 · mol−1
- ^ ΔfH°, -382.21 kJ · mol−1
- ^ ΔfH°, -677.98 kJ · mol−1
- ^ ΔfH°, 102.5 kJ · mol−1
- ^ ΔfG°, 120.5 kJ · mol−1
- ^ S°, 256.84 J · K−1 · mol−1
- ^ Cp°, 41.97 J · K−1 · mol−1
- ^ ΔfH°, 74.9 kJ · mol−1
- ^ ΔfG°, 120.1 kJ · mol−1
- ^ S°, 164.8 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