Mg3(AsO4)2 + 6HBr → 3MgBr2 + 2H3AsO4
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The reaction of magnesium arsenate and hydrogen bromide yields magnesium bromide and 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 magnesium arsenate and hydrogen bromide
General equation
- Salt of weak acidBrønsted base + Strong acidBrønsted acid ⟶ Salt of strong acidConjugate base + Weak acidConjugate acid
Oxidation state of each atom
- Reaction of magnesium arsenate and hydrogen bromide
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Mg3(AsO4)2 | Magnesium arsenate | 1 | Brønsted base | Salt of weak acid |
| HBr | Hydrogen bromide | 6 | Brønsted acid | Strong acid |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| MgBr2 | Magnesium bromide | 3 | Conjugate base | Salt of strong acid |
| H3AsO4 | Arsenic acid | 2 | Conjugate acid | Weak acid |
Thermodynamic changes
Changes in standard condition
- Reaction of magnesium arsenate and hydrogen bromide
| 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 | −74.3 | – | – | – |
per 1 mol of | −74.3 | – | – | – |
per 1 mol of | −12.4 | – | – | – |
per 1 mol of | −24.8 | – | – | – |
per 1 mol of | −37.1 | – | – | – |
Changes in aqueous solution (1)
- Reaction of magnesium arsenate and hydrogen bromide
- Mg3(AsO4)2Crystalline solid + 6HBrIonized aqueous solution3MgBr2Ionized aqueous solution + 2H3AsO4Un-ionized aqueous solution⟶
| 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 | −112.7 | – | – | – |
per 1 mol of | −112.7 | – | – | – |
per 1 mol of | −18.78 | – | – | – |
per 1 mol of | −37.57 | – | – | – |
per 1 mol of | −56.35 | – | – | – |
Changes in aqueous solution (2)
- Reaction of magnesium arsenate and hydrogen bromide
- Mg3(AsO4)2Crystalline solid + 6HBrIonized aqueous solution3MgBr2Ionized aqueous solution + 2H3AsO4Aqueous solution⟶
| 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 | −116.9 | – | – | – |
per 1 mol of | −116.9 | – | – | – |
per 1 mol of | −19.48 | – | – | – |
per 1 mol of | −38.97 | – | – | – |
per 1 mol of | −58.45 | – | – | – |
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 |
|---|---|---|---|---|
| Mg3(AsO4)2 (cr) | -3092.8[1] | – | – | – |
| HBr (g) | -36.40[1] | -53.45[1] | 198.695[1] | 29.142[1] |
| HBr (ai) | -121.55[1] | -103.96[1] | 82.4[1] | -141.8[1] |
* (cr):Crystalline solid, (g):Gas, (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 |
|---|---|---|---|---|
| MgBr2 (cr) | -524.3[1] | -503.8[1] | 117.2[1] | – |
| MgBr2 (g) | -309.6[1] | – | – | – |
| MgBr2 (ai) | -709.94[1] | -662.7[1] | 26.8[1] | – |
| MgBr2 (cr) 6 hydrate | -2410.0[1] | -2055.7[1] | 397[1] | – |
| H3AsO4 (cr) | -906.3[1] | – | – | – |
| H3AsO4 (ao) | -902.5[1] | -766.0[1] | 184[1] | – |
| H3AsO4 (aq) | -904.6[1] | – | – | – |
* (cr):Crystalline solid, (g):Gas, (ai):Ionized aqueous solution, (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°, -3092.8 kJ · mol−1
- ^ ΔfH°, -36.40 kJ · mol−1
- ^ ΔfG°, -53.45 kJ · mol−1
- ^ S°, 198.695 J · K−1 · mol−1
- ^ Cp°, 29.142 J · K−1 · mol−1
- ^ ΔfH°, -121.55 kJ · mol−1
- ^ ΔfG°, -103.96 kJ · mol−1
- ^ S°, 82.4 J · K−1 · mol−1
- ^ Cp°, -141.8 J · K−1 · mol−1
- ^ ΔfH°, -524.3 kJ · mol−1
- ^ ΔfG°, -503.8 kJ · mol−1
- ^ S°, 117.2 J · K−1 · mol−1
- ^ ΔfH°, -309.6 kJ · mol−1
- ^ ΔfH°, -709.94 kJ · mol−1
- ^ ΔfG°, -662.7 kJ · mol−1
- ^ S°, 26.8 J · K−1 · mol−1
- ^ ΔfH°, -2410.0 kJ · mol−1
- ^ ΔfG°, -2055.7 kJ · mol−1
- ^ S°, 397. 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