3KClO + H3PO4 → K3PO4 + HClO2 + Cl2↑ + H2O
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The reaction of potassium hypochlorite and phosphoric acid yields potassium phosphate, chlorous acid, , 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
- Reaction of potassium hypochlorite and phosphoric acid
General equation
- Reaction of self redoxing species and acid
- Self-redoxing speciesSelf redox agent + AcidNon-redox agent ⟶ ProductOxidation product + ProductReduction product
Oxidation state of each atom
- Reaction of potassium hypochlorite and phosphoric acid
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KClO | Potassium hypochlorite | 3 | – | Self redoxing |
| H3PO4 | Phosphoric acid | 1 | – | Acid |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K3PO4 | Potassium phosphate | 1 | – | – |
| HClO2 | Chlorous acid | 1 | Oxidized | – |
| 1 | Reduced | – | ||
| H2O | Water | 1 | – | – |
Thermodynamic changes
Changes in aqueous solution (1)
- Reaction of potassium hypochlorite and phosphoric acid◆
ΔrG 2.6 kJ/mol K 0.35 × 100 pK 0.46
| 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 | −5.9 | 2.6 | −28 | – |
per 1 mol of | −2.0 | 0.87 | −9.3 | – |
per 1 mol of | −5.9 | 2.6 | −28 | – |
per 1 mol of | −5.9 | 2.6 | −28 | – |
per 1 mol of | −5.9 | 2.6 | −28 | – |
| −5.9 | 2.6 | −28 | – | |
per 1 mol of | −5.9 | 2.6 | −28 | – |
Changes in aqueous solution (2)
- Reaction of potassium hypochlorite and phosphoric acid◆
ΔrG 9.6 kJ/mol K 0.21 × 10−1 pK 1.68
| 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 | −29.3 | 9.6 | −130 | – |
per 1 mol of | −9.77 | 3.2 | −43.3 | – |
per 1 mol of | −29.3 | 9.6 | −130 | – |
per 1 mol of | −29.3 | 9.6 | −130 | – |
per 1 mol of | −29.3 | 9.6 | −130 | – |
| −29.3 | 9.6 | −130 | – | |
per 1 mol of | −29.3 | 9.6 | −130 | – |
Changes in aqueous solution (3)
- Reaction of potassium hypochlorite and phosphoric acid◆
ΔrG −121.2 kJ/mol K 1.71 × 1021 pK −21.23
| 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 | −16.8 | −121.2 | 351 | – |
per 1 mol of | −5.60 | −40.40 | 117 | – |
per 1 mol of | −16.8 | −121.2 | 351 | – |
per 1 mol of | −16.8 | −121.2 | 351 | – |
per 1 mol of | −16.8 | −121.2 | 351 | – |
| −16.8 | −121.2 | 351 | – | |
per 1 mol of | −16.8 | −121.2 | 351 | – |
Changes in aqueous solution (4)
- Reaction of potassium hypochlorite and phosphoric acid◆
ΔrG −114.3 kJ/mol K 1.06 × 1020 pK −20.02
| 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 | −40.2 | −114.3 | 249 | – |
per 1 mol of | −13.4 | −38.10 | 83.0 | – |
per 1 mol of | −40.2 | −114.3 | 249 | – |
per 1 mol of | −40.2 | −114.3 | 249 | – |
per 1 mol of | −40.2 | −114.3 | 249 | – |
| −40.2 | −114.3 | 249 | – | |
per 1 mol of | −40.2 | −114.3 | 249 | – |
Changes in aqueous solution (5)
- Reaction of potassium hypochlorite and phosphoric acid◆
ΔrG 2.6 kJ/mol K 0.35 × 100 pK 0.46
| 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 | −5.9 | 2.6 | −28 | – |
per 1 mol of | −2.0 | 0.87 | −9.3 | – |
per 1 mol of | −5.9 | 2.6 | −28 | – |
per 1 mol of | −5.9 | 2.6 | −28 | – |
per 1 mol of | −5.9 | 2.6 | −28 | – |
| −5.9 | 2.6 | −28 | – | |
per 1 mol of | −5.9 | 2.6 | −28 | – |
Changes in aqueous solution (6)
- Reaction of potassium hypochlorite and phosphoric acid◆
ΔrG 9.6 kJ/mol K 0.21 × 10−1 pK 1.68
| 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 | −29.3 | 9.6 | −130 | – |
per 1 mol of | −9.77 | 3.2 | −43.3 | – |
per 1 mol of | −29.3 | 9.6 | −130 | – |
per 1 mol of | −29.3 | 9.6 | −130 | – |
per 1 mol of | −29.3 | 9.6 | −130 | – |
| −29.3 | 9.6 | −130 | – | |
per 1 mol of | −29.3 | 9.6 | −130 | – |
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 |
|---|---|---|---|---|
| KClO (ai) | -359.4[1] | -320.0[1] | 146[1] | – |
| H3PO4 (cr) | -1279.0[1] | -1119.1[1] | 110.50[1] | 106.06[1] |
| H3PO4 (l) | -1266.9[1] | – | – | – |
| H3PO4 (ai) | -1277.4[1] | -1018.7[1] | -220.3[1] | – |
| H3PO4 (ao) | -1288.34[1] | -1142.54[1] | 158.2[1] | – |
| H3PO4 (cr) 0.5 hydrate | -1431.3[1] | -1242.1[1] | 129.16[1] | 126.02[1] |
| H3PO4 (cr) 1 hydrate | -1568.83[1] | – | – | – |
* (ai):Ionized aqueous solution, (cr):Crystalline solid, (l):Liquid, (ao):Un-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 |
|---|---|---|---|---|
| K3PO4 (cr) | -1950.2[1] | – | – | – |
| K3PO4 (ai) | -2034.7[1] | -1868.7[1] | 87.2[1] | – |
| HClO2 (ao) | -51.9[1] | 5.9[1] | 188.3[1] | – |
| (g) | 0[1] | 0[1] | 223.066[1] | 33.907[1] |
| (ao) | -23.4[1] | 6.94[1] | 121[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, (ao):Un-ionized aqueous solution, (g):Gas, (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°, -359.4 kJ · mol−1
- ^ ΔfG°, -320.0 kJ · mol−1
- ^ S°, 146. J · K−1 · mol−1
- ^ ΔfH°, -1279.0 kJ · mol−1
- ^ ΔfG°, -1119.1 kJ · mol−1
- ^ S°, 110.50 J · K−1 · mol−1
- ^ Cp°, 106.06 J · K−1 · mol−1
- ^ ΔfH°, -1266.9 kJ · mol−1
- ^ ΔfH°, -1277.4 kJ · mol−1
- ^ ΔfG°, -1018.7 kJ · mol−1
- ^ S°, -220.3 J · K−1 · mol−1
- ^ ΔfH°, -1288.34 kJ · mol−1
- ^ ΔfG°, -1142.54 kJ · mol−1
- ^ S°, 158.2 J · K−1 · mol−1
- ^ ΔfH°, -1431.3 kJ · mol−1
- ^ ΔfG°, -1242.1 kJ · mol−1
- ^ S°, 129.16 J · K−1 · mol−1
- ^ Cp°, 126.02 J · K−1 · mol−1
- ^ ΔfH°, -1568.83 kJ · mol−1
- ^ ΔfH°, -1950.2 kJ · mol−1
- ^ ΔfH°, -2034.7 kJ · mol−1
- ^ ΔfG°, -1868.7 kJ · mol−1
- ^ S°, 87.2 J · K−1 · mol−1
- ^ ΔfH°, -51.9 kJ · mol−1
- ^ ΔfG°, 5.9 kJ · mol−1
- ^ S°, 188.3 J · K−1 · mol−1
- ^ ΔfH°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 223.066 J · K−1 · mol−1
- ^ Cp°, 33.907 J · K−1 · mol−1
- ^ ΔfH°, -23.4 kJ · mol−1
- ^ ΔfG°, 6.94 kJ · mol−1
- ^ S°, 121. 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