2KI + Na2Cr2O7 🔥→ K2O + NaIO3 + Cr2O3 + NaI
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The reaction of potassium iodide and sodium dichromate yields potassium oxide, sodium iodate, chromium(III) oxide, and sodium iodide (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 potassium iodide and sodium dichromate
General equation
- Reaction of oxidizable species and oxidizing species
- Oxidizable speciesReducing agent + Oxidizing speciesOxidizing agent ⟶ ProductOxidation product + ProductReduction product
Oxidation state of each atom
- Reaction of potassium iodide and sodium dichromate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KI | Potassium iodide | 2 | Reducing | Oxidizable |
| Na2Cr2O7 | Sodium dichromate | 1 | Oxidizing | Oxidizing |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K2O | Potassium oxide | 1 | – | – |
| NaIO3 | Sodium iodate | 1 | Oxidized | – |
| Cr2O3 | Chromium(III) oxide | 1 | Reduced | – |
| NaI | Sodium iodide | 1 | – | – |
Thermodynamic changes
Changes in standard condition
- Reaction of potassium iodide and sodium dichromate
| 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 | 363.6 | – | – | – |
per 1 mol of | 181.8 | – | – | – |
per 1 mol of | 363.6 | – | – | – |
per 1 mol of | 363.6 | – | – | – |
per 1 mol of | 363.6 | – | – | – |
per 1 mol of | 363.6 | – | – | – |
per 1 mol of | 363.6 | – | – | – |
Changes in aqueous solution
- Reaction of potassium iodide and sodium dichromate◆
ΔrG 411.0 kJ/mol K 0.99 × 10−72 pK 72.00
| 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 | 327.8 | 411.0 | −284.5 | – |
per 1 mol of | 163.9 | 205.5 | −142.3 | – |
per 1 mol of | 327.8 | 411.0 | −284.5 | – |
per 1 mol of | 327.8 | 411.0 | −284.5 | – |
per 1 mol of | 327.8 | 411.0 | −284.5 | – |
per 1 mol of | 327.8 | 411.0 | −284.5 | – |
per 1 mol of | 327.8 | 411.0 | −284.5 | – |
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 |
|---|---|---|---|---|
| KI (cr) | -327.900[1] | -324.892[1] | 106.32[1] | 52.93[1] |
| KI (g) | -125.5[1] | -166.1[1] | 258.3[1] | 37.11[1] |
| KI (ai) | -307.57[1] | -334.85[1] | 213.8[1] | -120.5[1] |
| Na2Cr2O7 (cr) | -1978.6[1] | – | – | – |
| Na2Cr2O7 (ai) | -1970.7[1] | -1824.9[1] | 379.9[1] | – |
| Na2Cr2O7 (cr) 2 hydrate | -2574.8[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 |
|---|---|---|---|---|
| K2O (cr) | -361.5[1] | -322.1[2] | 94.1[2] | 83.7[2] |
| K2O (g) | -63[1] | – | – | – |
| NaIO3 (cr) | -481.788[1] | – | – | 92.0[1] |
| NaIO3 (ai) | -461.5[1] | -389.9[1] | 177.4[1] | – |
| NaIO3 (cr) 1 hydrate | -779.48[1] | -634.03[1] | 162.3[1] | – |
| NaIO3 (cr) 5 hydrate | -1952.25[1] | – | – | – |
| Cr2O3 (cr) | -1139.7[1] | -1058.1[1] | 81.2[1] | 118.74[1] |
| Cr2O3 (cr) 1 hydrate | -1506[1] | – | – | – |
| Cr2O3 (cr) 2 hydrate | -1845[1] | – | – | – |
| Cr2O3 (cr) 3 hydrate | -2171[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] | – |
* (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°, -327.900 kJ · mol−1
- ^ ΔfG°, -324.892 kJ · mol−1
- ^ S°, 106.32 J · K−1 · mol−1
- ^ Cp°, 52.93 J · K−1 · mol−1
- ^ ΔfH°, -125.5 kJ · mol−1
- ^ ΔfG°, -166.1 kJ · mol−1
- ^ S°, 258.3 J · K−1 · mol−1
- ^ Cp°, 37.11 J · K−1 · mol−1
- ^ ΔfH°, -307.57 kJ · mol−1
- ^ ΔfG°, -334.85 kJ · mol−1
- ^ S°, 213.8 J · K−1 · mol−1
- ^ Cp°, -120.5 J · K−1 · mol−1
- ^ ΔfH°, -1978.6 kJ · mol−1
- ^ ΔfH°, -1970.7 kJ · mol−1
- ^ ΔfG°, -1824.9 kJ · mol−1
- ^ S°, 379.9 J · K−1 · mol−1
- ^ ΔfH°, -2574.8 kJ · mol−1
- ^ ΔfH°, -361.5 kJ · mol−1
- ^ ΔfH°, -63. kJ · mol−1
- ^ ΔfH°, -481.788 kJ · mol−1
- ^ Cp°, 92.0 J · K−1 · mol−1
- ^ ΔfH°, -461.5 kJ · mol−1
- ^ ΔfG°, -389.9 kJ · mol−1
- ^ S°, 177.4 J · K−1 · mol−1
- ^ ΔfH°, -779.48 kJ · mol−1
- ^ ΔfG°, -634.03 kJ · mol−1
- ^ S°, 162.3 J · K−1 · mol−1
- ^ ΔfH°, -1952.25 kJ · mol−1
- ^ ΔfH°, -1139.7 kJ · mol−1
- ^ ΔfG°, -1058.1 kJ · mol−1
- ^ S°, 81.2 J · K−1 · mol−1
- ^ Cp°, 118.74 J · K−1 · mol−1
- ^ ΔfH°, -1506. kJ · mol−1
- ^ ΔfH°, -1845. kJ · mol−1
- ^ ΔfH°, -2171. 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
- 2James G. Speight (2017)Lange's Handbook of Chemistry, 17th editionMcGraw Hill Education
- ^ ΔfG°, -322.1 kJ · mol−1 - p.280
- ^ S°, 94.1 J · K−1 · mol−1 - p.280
- ^ Cp°, 83.7 J · K−1 · mol−1 - p.280