3NH4F + H3PO4 🔥→ (NH4)3PO4 + 3HF↑
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The reaction of ammonium fluoride and phosphoric acid yields ammonium phosphate and hydrogen fluoride. This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Reaction of ammonium fluoride and phosphoric acid
General equation
- Salt of volatile acidBrønsted base + Nonvolatile acidBrønsted acid ⟶ Salt of non volatile acidConjugate base + Volatile acidConjugate acid
Oxidation state of each atom
- Reaction of ammonium fluoride and phosphoric acid
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| NH4F | Ammonium fluoride | 3 | Brønsted base | Salt of volatile acid |
| H3PO4 | Phosphoric acid | 1 | Brønsted acid | Nonvolatile acid |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| (NH4)3PO4 | Ammonium phosphate | 1 | Conjugate base | Salt of non volatile acid |
| HF | Hydrogen fluoride | 3 | Conjugate acid | Volatile acid |
Thermodynamic changes
Changes in standard condition
- Reaction of ammonium fluoride and phosphoric acid
| 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 | 185.7 | – | – | – |
per 1 mol of | 61.90 | – | – | – |
per 1 mol of | 185.7 | – | – | – |
per 1 mol of | 185.7 | – | – | – |
per 1 mol of | 61.90 | – | – | – |
Changes in aqueous solution (1)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG 140.6 kJ/mol K 0.23 × 10−24 pK 24.63
| 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 | 195.6 | 140.6 | 181 | – |
per 1 mol of | 65.20 | 46.87 | 60.3 | – |
per 1 mol of | 195.6 | 140.6 | 181 | – |
per 1 mol of | 195.6 | 140.6 | 181 | – |
per 1 mol of | 65.20 | 46.87 | 60.3 | – |
Changes in aqueous solution (2)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG 69.8 kJ/mol K 0.59 × 10−12 pK 12.23
| 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 | 48.6 | 69.8 | −74 | – |
per 1 mol of | 16.2 | 23.3 | −25 | – |
per 1 mol of | 48.6 | 69.8 | −74 | – |
per 1 mol of | 48.6 | 69.8 | −74 | – |
per 1 mol of | 16.2 | 23.3 | −25 | – |
Changes in aqueous solution (3)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG 69.8 kJ/mol K 0.59 × 10−12 pK 12.23
| 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 | 48.6 | 69.8 | −74 | – |
per 1 mol of | 16.2 | 23.3 | −25 | – |
per 1 mol of | 48.6 | 69.8 | −74 | – |
per 1 mol of | 48.6 | 69.8 | −74 | – |
per 1 mol of | 16.2 | 23.3 | −25 | – |
Changes in aqueous solution (4)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG 16.8 kJ/mol K 0.11 × 10−2 pK 2.94
| 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 | 184.6 | 16.8 | 560 | – |
per 1 mol of | 61.53 | 5.60 | 187 | – |
per 1 mol of | 184.6 | 16.8 | 560 | – |
per 1 mol of | 184.6 | 16.8 | 560 | – |
per 1 mol of | 61.53 | 5.60 | 187 | – |
Changes in aqueous solution (5)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG −54.1 kJ/mol K 3.01 × 109 pK −9.48
| 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 | 37.7 | −54.1 | 305 | – |
per 1 mol of | 12.6 | −18.0 | 102 | – |
per 1 mol of | 37.7 | −54.1 | 305 | – |
per 1 mol of | 37.7 | −54.1 | 305 | – |
per 1 mol of | 12.6 | −18.0 | 102 | – |
Changes in aqueous solution (6)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG −54.1 kJ/mol K 3.01 × 109 pK −9.48
| 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 | 37.7 | −54.1 | 305 | – |
per 1 mol of | 12.6 | −18.0 | 102 | – |
per 1 mol of | 37.7 | −54.1 | 305 | – |
per 1 mol of | 37.7 | −54.1 | 305 | – |
per 1 mol of | 12.6 | −18.0 | 102 | – |
Changes in aqueous solution (7)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG 140.6 kJ/mol K 0.23 × 10−24 pK 24.63
| 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 | 195.6 | 140.6 | 181 | – |
per 1 mol of | 65.20 | 46.87 | 60.3 | – |
per 1 mol of | 195.6 | 140.6 | 181 | – |
per 1 mol of | 195.6 | 140.6 | 181 | – |
per 1 mol of | 65.20 | 46.87 | 60.3 | – |
Changes in aqueous solution (8)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG 69.8 kJ/mol K 0.59 × 10−12 pK 12.23
| 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 | 48.6 | 69.8 | −74 | – |
per 1 mol of | 16.2 | 23.3 | −25 | – |
per 1 mol of | 48.6 | 69.8 | −74 | – |
per 1 mol of | 48.6 | 69.8 | −74 | – |
per 1 mol of | 16.2 | 23.3 | −25 | – |
Changes in aqueous solution (9)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG 69.8 kJ/mol K 0.59 × 10−12 pK 12.23
| 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 | 48.6 | 69.8 | −74 | – |
per 1 mol of | 16.2 | 23.3 | −25 | – |
per 1 mol of | 48.6 | 69.8 | −74 | – |
per 1 mol of | 48.6 | 69.8 | −74 | – |
per 1 mol of | 16.2 | 23.3 | −25 | – |
Changes in aqueous solution (10)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG 123.8 kJ/mol K 0.20 × 10−21 pK 21.69
| 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 | 11.0 | 123.8 | −381 | – |
per 1 mol of | 3.67 | 41.27 | −127 | – |
per 1 mol of | 11.0 | 123.8 | −381 | – |
per 1 mol of | 11.0 | 123.8 | −381 | – |
per 1 mol of | 3.67 | 41.27 | −127 | – |
Changes in aqueous solution (11)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG 0.0 kJ/mol K 1.00 × 100 pK 0.00
| 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 | 0.0 | 0.0 | −3 | – |
per 1 mol of | 0.0 | 0.0 | −1 | – |
per 1 mol of | 0.0 | 0.0 | −3 | – |
per 1 mol of | 0.0 | 0.0 | −3 | – |
per 1 mol of | 0.0 | 0.0 | −1 | – |
Changes in aqueous solution (12)
- Reaction of ammonium fluoride and phosphoric acid◆
ΔrG 123.8 kJ/mol K 0.20 × 10−21 pK 21.69
| 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 | 11.0 | 123.8 | −381 | – |
per 1 mol of | 3.67 | 41.27 | −127 | – |
per 1 mol of | 11.0 | 123.8 | −381 | – |
per 1 mol of | 11.0 | 123.8 | −381 | – |
per 1 mol of | 3.67 | 41.27 | −127 | – |
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 |
|---|---|---|---|---|
| NH4F (cr) | -463.96[1] | -348.68[1] | 71.96[1] | 65.27[1] |
| NH4F (ai) | -465.14[1] | -358.09[1] | 99.6[1] | -26.8[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] | – | – | – |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (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 |
|---|---|---|---|---|
| (NH4)3PO4 (cr) | -1671.9[1] | – | – | – |
| (NH4)3PO4 (ai) | -1674.9[1] | -1256.6[1] | 117[1] | – |
| (NH4)3PO4 (cr) 3 hydrate | -2555.6[1] | – | – | – |
| HF (l) x denotes undetermined zero point entropy | -299.78[1] | – | 75.40+x[1] | – |
| HF (g) | -271.1[1] | -273.2[1] | 173.779[1] | 29.133[1] |
| HF (ai) | -332.63[1] | -278.79[1] | -13.8[1] | -106.7[1] |
| HF (ao) | -320.08[1] | -296.82[1] | 88.7[1] | – |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (l):Liquid, (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°, -463.96 kJ · mol−1
- ^ ΔfG°, -348.68 kJ · mol−1
- ^ S°, 71.96 J · K−1 · mol−1
- ^ Cp°, 65.27 J · K−1 · mol−1
- ^ ΔfH°, -465.14 kJ · mol−1
- ^ ΔfG°, -358.09 kJ · mol−1
- ^ S°, 99.6 J · K−1 · mol−1
- ^ Cp°, -26.8 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°, -1671.9 kJ · mol−1
- ^ ΔfH°, -1674.9 kJ · mol−1
- ^ ΔfG°, -1256.6 kJ · mol−1
- ^ S°, 117. J · K−1 · mol−1
- ^ ΔfH°, -2555.6 kJ · mol−1
- ^ ΔfH°, -299.78 kJ · mol−1
- ^ S°, 75.40+x J · K−1 · mol−1
- ^ ΔfH°, -271.1 kJ · mol−1
- ^ ΔfG°, -273.2 kJ · mol−1
- ^ S°, 173.779 J · K−1 · mol−1
- ^ Cp°, 29.133 J · K−1 · mol−1
- ^ ΔfH°, -332.63 kJ · mol−1
- ^ ΔfG°, -278.79 kJ · mol−1
- ^ S°, -13.8 J · K−1 · mol−1
- ^ Cp°, -106.7 J · K−1 · mol−1
- ^ ΔfH°, -320.08 kJ · mol−1
- ^ ΔfG°, -296.82 kJ · mol−1
- ^ S°, 88.7 J · K−1 · mol−1