12Na2HPO4 🔥→ 8Na3PO4 + 3O2↑ + P4O10 + 6H2↑
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- Decomposition of sodium hydrogenphosphate
Decomposition of sodium hydrogenphosphate yields sodium phosphate, , tetraphosphorus decaoxide, and (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 sodium hydrogenphosphate
General equation
- Thermal decomposition with redox
- Thermally decomposable substanceSelf redox agent🔥⟶ ProductOxidation product + ProductReduction product
- Thermal decomposition of oxoacid salt with redox
- Oxoacid saltSelf redox agent🔥⟶ ProductOxidation product + ProductReduction product
Oxidation state of each atom
- Decomposition of sodium hydrogenphosphate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Na2HPO4 | Sodium hydrogenphosphate | 12 | Self redox agent | Thermally decomposable Oxoacid salt |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Na3PO4 | Sodium phosphate | 8 | – | – |
| 3 | Oxidized | – | ||
| P4O10 | Tetraphosphorus decaoxide | 1 | – | – |
| 6 | Reduced | – |
Thermodynamic changes
Changes in standard condition (1)
- Decomposition of sodium hydrogenphosphate◆
ΔrG 2290.3 kJ/mol K 0.57 × 10−401 pK 401.24
| 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 | 2654.0 | 2290.3 | 1212.78 | 76.76 |
per 1 mol of | 221.17 | 190.86 | 101.065 | 6.397 |
per 1 mol of | 331.75 | 286.29 | 151.597 | 9.595 |
| 884.67 | 763.43 | 404.260 | 25.59 | |
per 1 mol of | 2654.0 | 2290.3 | 1212.78 | 76.76 |
| 442.33 | 381.72 | 202.130 | 12.79 |
Changes in standard condition (2)
- Decomposition of sodium hydrogenphosphate
| 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 | 2596 | – | – | – |
per 1 mol of | 216.3 | – | – | – |
per 1 mol of | 324.5 | – | – | – |
| 865.3 | – | – | – | |
per 1 mol of | 2596 | – | – | – |
| 432.7 | – | – | – |
Changes in aqueous solution (1)
- Decomposition of sodium hydrogenphosphate◆
ΔrG 2222.1 kJ/mol K 0.51 × 10−389 pK 389.30
| 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 | 2301.4 | 2222.1 | 268.0 | – |
per 1 mol of | 191.78 | 185.17 | 22.33 | – |
per 1 mol of | 287.68 | 277.76 | 33.50 | – |
| 767.13 | 740.70 | 89.33 | – | |
per 1 mol of | 2301.4 | 2222.1 | 268.0 | – |
| 383.57 | 370.35 | 44.67 | – |
Changes in aqueous solution (2)
- Decomposition of sodium hydrogenphosphate◆
ΔrG 2327.7 kJ/mol K 0.16 × 10−407 pK 407.80
| 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 | 2276.2 | 2327.7 | 2946 | – |
per 1 mol of | 189.68 | 193.97 | 245.5 | – |
per 1 mol of | 284.52 | 290.96 | 368.3 | – |
| 758.73 | 775.90 | 982.0 | – | |
per 1 mol of | 2276.2 | 2327.7 | 2946 | – |
| 379.37 | 387.95 | 491.0 | – |
Changes in aqueous solution (3)
- Decomposition of sodium hydrogenphosphate◆
ΔrG 2271.3 kJ/mol K 0.12 × 10−397 pK 397.91
| 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 | 2266.3 | 2271.3 | −14.7 | – |
per 1 mol of | 188.86 | 189.28 | −1.22 | – |
per 1 mol of | 283.29 | 283.91 | −1.84 | – |
| 755.43 | 757.10 | −4.90 | – | |
per 1 mol of | 2266.3 | 2271.3 | −14.7 | – |
| 377.72 | 378.55 | −2.45 | – |
Changes in aqueous solution (4)
- Decomposition of sodium hydrogenphosphate◆
ΔrG 2376.9 kJ/mol K 0.38 × 10−416 pK 416.41
| 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 | 2241.1 | 2376.9 | 2663 | – |
per 1 mol of | 186.76 | 198.08 | 221.9 | – |
per 1 mol of | 280.14 | 297.11 | 332.9 | – |
| 747.03 | 792.30 | 887.7 | – | |
per 1 mol of | 2241.1 | 2376.9 | 2663 | – |
| 373.52 | 396.15 | 443.8 | – |
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 |
|---|---|---|---|---|
| Na2HPO4 (cr) | -1748.1[1] | -1608.2[1] | 150.50[1] | 135.31[1] |
| Na2HPO4 (ai) | -1772.38[1] | -1612.98[1] | 84.5[1] | – |
| Na2HPO4 (cr) 2 hydrate | -2346.0[1] | -2088.5[1] | 221.3[1] | – |
| Na2HPO4 (cr) 7 hydrate | -3821.7[1] | -3279.8[1] | 434.59[1] | – |
| Na2HPO4 (cr) 12 hydrate | -5297.8[1] | -4467.8[1] | 633.83[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 |
|---|---|---|---|---|
| Na3PO4 (cr) | -1917.40[1] | -1788.80[1] | 173.80[1] | 153.47[1] |
| Na3PO4 (ai) | -1997.9[1] | -1804.5[1] | -43.3[1] | – |
| (g) | 0[1] | 0[1] | 205.138[1] | 29.355[1] |
| (ao) | -11.7[1] | 16.4[1] | 110.9[1] | – |
| P4O10 (cr) hexagonal | -2984.0[1] | -2697.7[1] | 228.86[1] | 211.71[1] |
| P4O10 (am) | -3042[1] | – | – | – |
| (g) | 0[1] | 0[1] | 130.684[1] | 28.824[1] |
| (ao) | -4.2[1] | 17.6[1] | 577[1] | – |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (g):Gas, (ao):Un-ionized aqueous solution, (am):Amorphous solid
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°, -1748.1 kJ · mol−1
- ^ ΔfG°, -1608.2 kJ · mol−1
- ^ S°, 150.50 J · K−1 · mol−1
- ^ Cp°, 135.31 J · K−1 · mol−1
- ^ ΔfH°, -1772.38 kJ · mol−1
- ^ ΔfG°, -1612.98 kJ · mol−1
- ^ S°, 84.5 J · K−1 · mol−1
- ^ ΔfH°, -2346.0 kJ · mol−1
- ^ ΔfG°, -2088.5 kJ · mol−1
- ^ S°, 221.3 J · K−1 · mol−1
- ^ ΔfH°, -3821.7 kJ · mol−1
- ^ ΔfG°, -3279.8 kJ · mol−1
- ^ S°, 434.59 J · K−1 · mol−1
- ^ ΔfH°, -5297.8 kJ · mol−1
- ^ ΔfG°, -4467.8 kJ · mol−1
- ^ S°, 633.83 J · K−1 · mol−1
- ^ ΔfH°, -1917.40 kJ · mol−1
- ^ ΔfG°, -1788.80 kJ · mol−1
- ^ S°, 173.80 J · K−1 · mol−1
- ^ Cp°, 153.47 J · K−1 · mol−1
- ^ ΔfH°, -1997.9 kJ · mol−1
- ^ ΔfG°, -1804.5 kJ · mol−1
- ^ S°, -43.3 J · K−1 · mol−1
- ^ ΔfH°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 205.138 J · K−1 · mol−1
- ^ Cp°, 29.355 J · K−1 · mol−1
- ^ ΔfH°, -11.7 kJ · mol−1
- ^ ΔfG°, 16.4 kJ · mol−1
- ^ S°, 110.9 J · K−1 · mol−1
- ^ ΔfH°, -2984.0 kJ · mol−1
- ^ ΔfG°, -2697.7 kJ · mol−1
- ^ S°, 228.86 J · K−1 · mol−1
- ^ Cp°, 211.71 J · K−1 · mol−1
- ^ ΔfH°, -3042. kJ · mol−1
- ^ ΔfH°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 130.684 J · K−1 · mol−1
- ^ Cp°, 28.824 J · K−1 · mol−1
- ^ ΔfH°, -4.2 kJ · mol−1
- ^ ΔfG°, 17.6 kJ · mol−1
- ^ S°, 577 J · K−1 · mol−1