Zn(SCN)2 + 4Mg(OH)2 → 2MgS + 2MgCO3 + Zn(OH)2 + 2NH3↑
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The reaction of zinc thiocyanate and magnesium hydroxide yields magnesium sulfide, magnesium carbonate, zinc hydroxide, and ammonia. This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Reaction of zinc thiocyanate and magnesium hydroxide
General equation
- Reaction of salt of weak base and strong base
- Salt of weak baseBrønsted acid + Strong baseBrønsted base ⟶ Salt of strong baseConjugate acid + Weak baseConjugate base + (H2O)
Oxidation state of each atom
- Reaction of zinc thiocyanate and magnesium hydroxide
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Zn(SCN)2 | Zinc thiocyanate | 1 | Brønsted acid | Salt of weak base |
| Mg(OH)2 | Magnesium hydroxide | 4 | Brønsted base | Strong base |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| MgS | Magnesium sulfide | 2 | Conjugate acid | Salt of strong base |
| MgCO3 | Magnesium carbonate | 2 | Conjugate acid | Salt of strong base |
| Zn(OH)2 | Zinc hydroxide | 1 | Conjugate base | Weak base |
| NH3 | Ammonia | 2 | Conjugate base | Weak base |
Thermodynamic changes
Changes in aqueous solution (1)
- Reaction of zinc thiocyanate and magnesium hydroxide◆
ΔrG 37.5 kJ/mol K 0.27 × 10−6 pK 6.57
| 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 | – | 37.5 | – | – |
per 1 mol of | – | 37.5 | – | – |
per 1 mol of | – | 9.38 | – | – |
per 1 mol of | – | 18.8 | – | – |
per 1 mol of | – | 18.8 | – | – |
per 1 mol of | – | 37.5 | – | – |
per 1 mol of | – | 18.8 | – | – |
Changes in aqueous solution (2)
- Reaction of zinc thiocyanate and magnesium hydroxide◆
ΔrG 17.4 kJ/mol K 0.89 × 10−3 pK 3.05
| 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 | – | 17.4 | – | – |
per 1 mol of | – | 17.4 | – | – |
per 1 mol of | – | 4.35 | – | – |
per 1 mol of | – | 8.70 | – | – |
per 1 mol of | – | 8.70 | – | – |
per 1 mol of | – | 17.4 | – | – |
per 1 mol of | – | 8.70 | – | – |
Changes in aqueous solution (3)
- Reaction of zinc thiocyanate and magnesium hydroxide◆
ΔrG 6.4 kJ/mol K 0.76 × 10−1 pK 1.12
| 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 | – | 6.4 | – | – |
per 1 mol of | – | 6.4 | – | – |
per 1 mol of | – | 1.6 | – | – |
per 1 mol of | – | 3.2 | – | – |
per 1 mol of | – | 3.2 | – | – |
per 1 mol of | – | 6.4 | – | – |
per 1 mol of | – | 3.2 | – | – |
Changes in aqueous solution (4)
- Reaction of zinc thiocyanate and magnesium hydroxide◆
ΔrG −13.7 kJ/mol K 2.51 × 102 pK −2.40
| 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 | – | −13.7 | – | – |
per 1 mol of | – | −13.7 | – | – |
per 1 mol of | – | −3.42 | – | – |
per 1 mol of | – | −6.85 | – | – |
per 1 mol of | – | −6.85 | – | – |
per 1 mol of | – | −13.7 | – | – |
per 1 mol of | – | −6.85 | – | – |
Changes in aqueous solution (5)
- Reaction of zinc thiocyanate and magnesium hydroxide◆
ΔrG 6.7 kJ/mol K 0.67 × 10−1 pK 1.17
| 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 | – | 6.7 | – | – |
per 1 mol of | – | 6.7 | – | – |
per 1 mol of | – | 1.7 | – | – |
per 1 mol of | – | 3.4 | – | – |
per 1 mol of | – | 3.4 | – | – |
per 1 mol of | – | 6.7 | – | – |
per 1 mol of | – | 3.4 | – | – |
Changes in aqueous solution (6)
- Reaction of zinc thiocyanate and magnesium hydroxide◆
ΔrG −13.4 kJ/mol K 2.23 × 102 pK −2.35
| 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 | – | −13.4 | – | – |
per 1 mol of | – | −13.4 | – | – |
per 1 mol of | – | −3.35 | – | – |
per 1 mol of | – | −6.70 | – | – |
per 1 mol of | – | −6.70 | – | – |
per 1 mol of | – | −13.4 | – | – |
per 1 mol of | – | −6.70 | – | – |
Changes in aqueous solution (7)
- Reaction of zinc thiocyanate and magnesium hydroxide◆
ΔrG 5.2 kJ/mol K 0.12 × 100 pK 0.91
| 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 | – | 5.2 | – | – |
per 1 mol of | – | 5.2 | – | – |
per 1 mol of | – | 1.3 | – | – |
per 1 mol of | – | 2.6 | – | – |
per 1 mol of | – | 2.6 | – | – |
per 1 mol of | – | 5.2 | – | – |
per 1 mol of | – | 2.6 | – | – |
Changes in aqueous solution (8)
- Reaction of zinc thiocyanate and magnesium hydroxide◆
ΔrG −14.9 kJ/mol K 4.08 × 102 pK −2.61
| 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 | – | −14.9 | – | – |
per 1 mol of | – | −14.9 | – | – |
per 1 mol of | – | −3.73 | – | – |
per 1 mol of | – | −7.45 | – | – |
per 1 mol of | – | −7.45 | – | – |
per 1 mol of | – | −14.9 | – | – |
per 1 mol of | – | −7.45 | – | – |
Changes in aqueous solution (9)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
Changes in aqueous solution (10)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
Changes in aqueous solution (11)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
Changes in aqueous solution (12)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
Changes in aqueous solution (13)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
Changes in aqueous solution (14)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
Changes in aqueous solution (15)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
Changes in aqueous solution (16)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
Changes in aqueous solution (17)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
Changes in aqueous solution (18)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
Changes in aqueous solution (19)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
Changes in aqueous solution (20)
- Reaction of zinc thiocyanate and magnesium hydroxide
| 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 | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
per 1 mol of | – | – | – | – |
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 |
|---|---|---|---|---|
| Zn(SCN)2 (ao) | – | 33.1[1] | – | – |
| Mg(OH)2 (cr) | -924.54[1] | -833.51[1] | 63.18[1] | 77.03[1] |
| Mg(OH)2 (am) precipitated | -920.5[1] | – | – | – |
| Mg(OH)2 (g) | -561[1] | – | – | – |
| Mg(OH)2 (ai) | -926.84[1] | -769.4[1] | -159.4[1] | – |
* (ao):Un-ionized aqueous solution, (cr):Crystalline solid, (am):Amorphous 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 |
|---|---|---|---|---|
| MgS (cr) | -346.0[1] | -341.8[1] | 50.33[1] | 45.56[1] |
| MgCO3 (cr) | -1095.8[1] | -1012.1[1] | 65.7[1] | 75.52[1] |
| MgCO3 (cr) 3 hydrate | – | -1726.1[1] | – | – |
| MgCO3 (cr) 5 hydrate | – | -2199.2[1] | – | – |
| Zn(OH)2 (cr) γ | – | -553.81[1] | – | – |
| Zn(OH)2 (cr) β | -641.91[1] | -553.52[1] | 81.2[1] | – |
| Zn(OH)2 (cr) ε | -643.25[1] | -555.07[1] | 81.6[1] | 72.4[1] |
| Zn(OH)2 (cr) precipitated | -642.2[1] | – | – | – |
| Zn(OH)2 (ai) | -613.88[1] | -461.56[1] | -133.5[1] | -251[1] |
| Zn(OH)2 (ao) | – | -522.73[1] | – | – |
| NH3 (g) | -46.11[1] | -16.45[1] | 192.45[1] | 35.06[1] |
| NH3 (ao) | -80.29[1] | -26.50[1] | 111.3[1] | – |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (ao):Un-ionized aqueous solution, (g):Gas
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)
- ^ ΔfG°, 33.1 kJ · mol−1
- ^ ΔfH°, -924.54 kJ · mol−1
- ^ ΔfG°, -833.51 kJ · mol−1
- ^ S°, 63.18 J · K−1 · mol−1
- ^ Cp°, 77.03 J · K−1 · mol−1
- ^ ΔfH°, -920.5 kJ · mol−1
- ^ ΔfH°, -561. kJ · mol−1
- ^ ΔfH°, -926.84 kJ · mol−1
- ^ ΔfG°, -769.4 kJ · mol−1
- ^ S°, -159.4 J · K−1 · mol−1
- ^ ΔfH°, -346.0 kJ · mol−1
- ^ ΔfG°, -341.8 kJ · mol−1
- ^ S°, 50.33 J · K−1 · mol−1
- ^ Cp°, 45.56 J · K−1 · mol−1
- ^ ΔfH°, -1095.8 kJ · mol−1
- ^ ΔfG°, -1012.1 kJ · mol−1
- ^ S°, 65.7 J · K−1 · mol−1
- ^ Cp°, 75.52 J · K−1 · mol−1
- ^ ΔfG°, -1726.1 kJ · mol−1
- ^ ΔfG°, -2199.2 kJ · mol−1
- ^ ΔfG°, -553.81 kJ · mol−1
- ^ ΔfH°, -641.91 kJ · mol−1
- ^ ΔfG°, -553.52 kJ · mol−1
- ^ S°, 81.2 J · K−1 · mol−1
- ^ ΔfH°, -643.25 kJ · mol−1
- ^ ΔfG°, -555.07 kJ · mol−1
- ^ S°, 81.6 J · K−1 · mol−1
- ^ Cp°, 72.4 J · K−1 · mol−1
- ^ ΔfH°, -642.2 kJ · mol−1
- ^ ΔfH°, -613.88 kJ · mol−1
- ^ ΔfG°, -461.56 kJ · mol−1
- ^ S°, -133.5 J · K−1 · mol−1
- ^ Cp°, -251. J · K−1 · mol−1
- ^ ΔfG°, -522.73 kJ · mol−1
- ^ ΔfH°, -46.11 kJ · mol−1
- ^ ΔfG°, -16.45 kJ · mol−1
- ^ S°, 192.45 J · K−1 · mol−1
- ^ Cp°, 35.06 J · K−1 · mol−1
- ^ ΔfH°, -80.29 kJ · mol−1
- ^ ΔfG°, -26.50 kJ · mol−1
- ^ S°, 111.3 J · K−1 · mol−1