2As + 2H3BO3 🔥→ H3AsO3 + AsH3↑ + B2O3
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- Reaction of and boric acid
The reaction of and boric acid yields arsenous acid, , and diboron trioxide (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 and boric 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 and boric acid
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| 2 | – | Self redoxing | ||
| H3BO3 | Boric acid | 2 | – | Acid |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| H3AsO3 | Arsenous acid | 1 | Oxidized | – |
| 1 | Reduced | – | ||
| B2O3 | Diboron trioxide | 1 | – | – |
Thermodynamic changes
Changes in aqueous solution (1)
- Reaction of and boric acid◆
ΔrG 172.98 kJ/mol K 0.50 × 10−30 pK 30.30
| 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 | 196.1 | 172.98 | 77.0 | – |
| 98.05 | 86.490 | 38.5 | – | |
per 1 mol of | 98.05 | 86.490 | 38.5 | – |
per 1 mol of | 196.1 | 172.98 | 77.0 | – |
| 196.1 | 172.98 | 77.0 | – | |
per 1 mol of | 196.1 | 172.98 | 77.0 | – |
Changes in aqueous solution (2)
- Reaction of and boric 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 | 196.1 | – | – | – |
| 98.05 | – | – | – | |
per 1 mol of | 98.05 | – | – | – |
per 1 mol of | 196.1 | – | – | – |
| 196.1 | – | – | – | |
per 1 mol of | 196.1 | – | – | – |
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 |
|---|---|---|---|---|
| (cr) α, gray, metallic | 0[1] | 0[1] | 35.1[1] | 24.64[1] |
| (cr) γ, yellow, cubic | 14.6[1] | – | – | – |
| (am) β | 4.2[1] | – | – | – |
| (g) | 302.5[1] | 261.0[1] | 174.21[1] | 20.786[1] |
| H3BO3 (cr) | -1094.33[1] | -968.92[1] | 88.83[1] | 81.38[1] |
| H3BO3 (g) | -994.1[1] | – | – | – |
| H3BO3 (ao) | -1072.32[1] | -968.75[1] | 162.3[1] | – |
* (cr):Crystalline solid, (am):Amorphous solid, (g):Gas, (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 |
|---|---|---|---|---|
| H3AsO3 (ao) | -742.2[1] | -639.80[1] | 195.0[1] | – |
| H3AsO3 (aq) | -742.2[1] | – | – | – |
| (g) | 66.44[1] | 68.93[1] | 222.78[1] | 38.07[1] |
| B2O3 (cr) | -1272.77[1] | -1193.65[1] | 53.97[1] | 62.93[1] |
| B2O3 (am) | -1254.53[1] | -1182.3[1] | 77.8[1] | 61.1[1] |
| B2O3 (g) | -843.79[1] | -831.97[1] | 279.81[1] | 66.86[1] |
* (ao):Un-ionized aqueous solution, (aq):Aqueous solution, (g):Gas, (cr):Crystalline solid, (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°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 35.1 J · K−1 · mol−1
- ^ Cp°, 24.64 J · K−1 · mol−1
- ^ ΔfH°, 14.6 kJ · mol−1
- ^ ΔfH°, 4.2 kJ · mol−1
- ^ ΔfH°, 302.5 kJ · mol−1
- ^ ΔfG°, 261.0 kJ · mol−1
- ^ S°, 174.21 J · K−1 · mol−1
- ^ Cp°, 20.786 J · K−1 · mol−1
- ^ ΔfH°, -1094.33 kJ · mol−1
- ^ ΔfG°, -968.92 kJ · mol−1
- ^ S°, 88.83 J · K−1 · mol−1
- ^ Cp°, 81.38 J · K−1 · mol−1
- ^ ΔfH°, -994.1 kJ · mol−1
- ^ ΔfH°, -1072.32 kJ · mol−1
- ^ ΔfG°, -968.75 kJ · mol−1
- ^ S°, 162.3 J · K−1 · mol−1
- ^ ΔfH°, -742.2 kJ · mol−1
- ^ ΔfG°, -639.80 kJ · mol−1
- ^ S°, 195.0 J · K−1 · mol−1
- ^ ΔfH°, -742.2 kJ · mol−1
- ^ ΔfH°, 66.44 kJ · mol−1
- ^ ΔfG°, 68.93 kJ · mol−1
- ^ S°, 222.78 J · K−1 · mol−1
- ^ Cp°, 38.07 J · K−1 · mol−1
- ^ ΔfH°, -1272.77 kJ · mol−1
- ^ ΔfG°, -1193.65 kJ · mol−1
- ^ S°, 53.97 J · K−1 · mol−1
- ^ Cp°, 62.93 J · K−1 · mol−1
- ^ ΔfH°, -1254.53 kJ · mol−1
- ^ ΔfG°, -1182.3 kJ · mol−1
- ^ S°, 77.8 J · K−1 · mol−1
- ^ Cp°, 61.1 J · K−1 · mol−1
- ^ ΔfH°, -843.79 kJ · mol−1
- ^ ΔfG°, -831.97 kJ · mol−1
- ^ S°, 279.81 J · K−1 · mol−1
- ^ Cp°, 66.86 J · K−1 · mol−1