ZnI2 + 2NaSCN 💧→ Zn(SCN)2↓ + 2NaI
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- Reaction of zinc iodide and sodium thiocyanate
The reaction of zinc iodide and sodium thiocyanate yields zinc thiocyanate and sodium iodide. This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Reaction of zinc iodide and sodium thiocyanate
General equation
- Precipitation reaction
- Miscible with water/Very soluble in water/Soluble in waterLewis acid + Miscible with water/Very soluble in water/Soluble in waterLewis base💧⟶ Insoluble in water/Very slightly soluble in water/Slightly soluble in waterLewis conjugate + Product(Non-redox product)
Oxidation state of each atom
- Reaction of zinc iodide and sodium thiocyanate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| ZnI2 | Zinc iodide | 1 | Lewis acid | Very soluble in water |
| NaSCN | Sodium thiocyanate | 2 | Lewis base | Very soluble in water |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Zn(SCN)2 | Zinc thiocyanate | 1 | Lewis conjugate | Slightly soluble in water |
| NaI | Sodium iodide | 2 | Non-redox product | – |
Thermodynamic changes
Changes in aqueous solution (1)
- Reaction of zinc iodide and sodium thiocyanate◆
ΔrG −5.3 kJ/mol K 8.48 × 100 pK −0.93
| 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 | – | −5.3 | – | – |
per 1 mol of | – | −5.3 | – | – |
per 1 mol of | – | −2.6 | – | – |
per 1 mol of | – | −5.3 | – | – |
per 1 mol of | – | −2.6 | – | – |
Changes in aqueous solution (2)
- Reaction of zinc iodide and sodium thiocyanate◆
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 | – | −7.45 | – | – |
per 1 mol of | – | −14.9 | – | – |
per 1 mol of | – | −7.45 | – | – |
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 |
|---|---|---|---|---|
| ZnI2 (cr) | -208.03[1] | -208.95[1] | 161.1[1] | – |
| ZnI2 (ai) | -264.26[1] | -250.20[1] | 110.5[1] | -238[1] |
| ZnI2 (ao) | – | -240.6[1] | – | – |
| NaSCN (cr) | -170.50[1] | – | – | – |
| NaSCN (ai) | -163.68[1] | -169.18[1] | 203.3[1] | 6.3[1] |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (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 |
|---|---|---|---|---|
| Zn(SCN)2 (ao) | – | 33.1[1] | – | – |
| NaI (cr) | -287.78[1] | -286.06[1] | 98.53[1] | 52.09[1] |
| NaI (g) | -79.5[1] | -121.0[1] | 248.978[1] | 36.65[1] |
| NaI (ai) | -295.31[1] | -313.47[1] | 170.3[1] | -95.8[1] |
| NaI (cr) 1 hydrate | -883.096[1] | -771.10[1] | 196.2[1] | – |
* (ao):Un-ionized aqueous solution, (cr):Crystalline solid, (g):Gas, (ai):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°, -208.03 kJ · mol−1
- ^ ΔfG°, -208.95 kJ · mol−1
- ^ S°, 161.1 J · K−1 · mol−1
- ^ ΔfH°, -264.26 kJ · mol−1
- ^ ΔfG°, -250.20 kJ · mol−1
- ^ S°, 110.5 J · K−1 · mol−1
- ^ Cp°, -238. J · K−1 · mol−1
- ^ ΔfG°, -240.6 kJ · mol−1
- ^ ΔfH°, -170.50 kJ · mol−1
- ^ ΔfH°, -163.68 kJ · mol−1
- ^ ΔfG°, -169.18 kJ · mol−1
- ^ S°, 203.3 J · K−1 · mol−1
- ^ Cp°, 6.3 J · K−1 · mol−1
- ^ ΔfG°, 33.1 kJ · mol−1
- ^ ΔfH°, -287.78 kJ · mol−1
- ^ ΔfG°, -286.06 kJ · mol−1
- ^ S°, 98.53 J · K−1 · mol−1
- ^ Cp°, 52.09 J · K−1 · mol−1
- ^ ΔfH°, -79.5 kJ · mol−1
- ^ ΔfG°, -121.0 kJ · mol−1
- ^ S°, 248.978 J · K−1 · mol−1
- ^ Cp°, 36.65 J · K−1 · mol−1
- ^ ΔfH°, -295.31 kJ · mol−1
- ^ ΔfG°, -313.47 kJ · mol−1
- ^ S°, 170.3 J · K−1 · mol−1
- ^ Cp°, -95.8 J · K−1 · mol−1
- ^ ΔfH°, -883.096 kJ · mol−1
- ^ ΔfG°, -771.10 kJ · mol−1
- ^ S°, 196.2 J · K−1 · mol−1