As2O5 + 3H2O → 2H3AsO4
Last updated:
- Reaction of diarsenic pentaoxide and water
The reaction of diarsenic pentaoxide and water yields arsenic acid (Other reactions are here). This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Reaction of diarsenic pentaoxide and water
General equation
- Reaction of acidic oxide and water
- Acidic oxideLewis acid + H2OLewis base ⟶ AcidLewis conjugate
- Reaction of weakly acidic oxide and water
- Weakly acidic oxideLewis acid + H2OLewis base ⟶ Weak acidLewis conjugate
Oxidation state of each atom
- Reaction of diarsenic pentaoxide and water
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| As2O5 | Diarsenic pentaoxide | 1 | Lewis acid | Acidic oxide Weakly acidic oxide |
| H2O | Water | 3 | Lewis base | Water |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| H3AsO4 | Arsenic acid | 2 | Lewis conjugate | Acid Weak acid |
Thermodynamic changes
Changes in standard condition
- Reaction of diarsenic pentaoxide and water
| 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 | −30.2 | – | – | – |
per 1 mol of | −30.2 | – | – | – |
per 1 mol of | −10.1 | – | – | – |
per 1 mol of | −15.1 | – | – | – |
Changes in aqueous solution (1)
- Reaction of diarsenic pentaoxide and water
| 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 | 3.9 | – | – | – |
per 1 mol of | 3.9 | – | – | – |
per 1 mol of | 1.3 | – | – | – |
per 1 mol of | 1.9 | – | – | – |
Changes in aqueous solution (2)
- Reaction of diarsenic pentaoxide and water
| 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 | −0.3 | – | – | – |
per 1 mol of | −0.30 | – | – | – |
per 1 mol of | −0.10 | – | – | – |
per 1 mol of | −0.15 | – | – | – |
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 |
|---|---|---|---|---|
| As2O5 (cr) | -924.87[1] | -782.3[1] | 105.4[1] | 116.52[1] |
| As2O5 (aq) | -951.4[1] | – | – | – |
| As2O5 (cr) 4 hydrate | -2104.6[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, (aq):Aqueous solution, (l):Liquid, (g):Gas
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 |
|---|---|---|---|---|
| H3AsO4 (cr) | -906.3[1] | – | – | – |
| H3AsO4 (ao) | -902.5[1] | -766.0[1] | 184[1] | – |
| H3AsO4 (aq) | -904.6[1] | – | – | – |
* (cr):Crystalline solid, (ao):Un-ionized aqueous solution, (aq):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°, -924.87 kJ · mol−1
- ^ ΔfG°, -782.3 kJ · mol−1
- ^ S°, 105.4 J · K−1 · mol−1
- ^ Cp°, 116.52 J · K−1 · mol−1
- ^ ΔfH°, -951.4 kJ · mol−1
- ^ ΔfH°, -2104.6 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
- ^ ΔfH°, -906.3 kJ · mol−1
- ^ ΔfH°, -902.5 kJ · mol−1
- ^ ΔfG°, -766.0 kJ · mol−1
- ^ S°, 184. J · K−1 · mol−1
- ^ ΔfH°, -904.6 kJ · mol−1