2K2SeO3 + Na2Cr2O7 💧→ 2K2CrO4↓ + Na2SeO3 + SeO2
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The reaction of potassium selenite and sodium dichromate yields potassium chromate, sodium selenite, and selenium dioxide (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 potassium selenite and sodium dichromate
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 potassium selenite and sodium dichromate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K2SeO3 | Potassium selenite | 2 | Lewis acid | Very soluble in water |
| Na2Cr2O7 | Sodium dichromate | 1 | Lewis base | Very soluble in water |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K2CrO4 | Potassium chromate | 2 | Lewis conjugate | Insoluble in water |
| Na2SeO3 | Sodium selenite | 1 | Non-redox product | – |
| SeO2 | Selenium dioxide | 1 | Non-redox product | – |
Thermodynamic changes
Changes in standard condition
- Reaction of potassium selenite 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 | −48.8 | – | – | – |
per 1 mol of | −24.4 | – | – | – |
per 1 mol of | −48.8 | – | – | – |
per 1 mol of | −24.4 | – | – | – |
per 1 mol of | −48.8 | – | – | – |
per 1 mol of | −48.8 | – | – | – |
Changes in aqueous solution
- Reaction of potassium selenite 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 | 15.4 | – | – | – |
per 1 mol of | 7.70 | – | – | – |
per 1 mol of | 15.4 | – | – | – |
per 1 mol of | 7.70 | – | – | – |
per 1 mol of | 15.4 | – | – | – |
per 1 mol of | 15.4 | – | – | – |
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 |
|---|---|---|---|---|
| K2SeO3 (cr) | -982.0[1] | – | – | – |
| K2SeO3 (ai) | -1013.8[1] | -936.3[1] | 218.0[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, (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 |
|---|---|---|---|---|
| K2CrO4 (cr) | -1403.7[1] | -1295.7[1] | 200.12[1] | 145.98[1] |
| K2CrO4 (ai) | -1385.91[1] | -1294.30[1] | 255.2[1] | – |
| Na2SeO3 (cr) | -958.6[1] | – | – | – |
| Na2SeO3 (ai) | -989.5[1] | -893.7[1] | 130[1] | – |
| Na2SeO3 (cr) 5 hydrate | -2404.13[1] | – | – | – |
| SeO2 (cr) | -225.35[1] | – | – | – |
| SeO2 (aq) | -221.63[1] | – | – | – |
* (cr):Crystalline solid, (ai):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°, -982.0 kJ · mol−1
- ^ ΔfH°, -1013.8 kJ · mol−1
- ^ ΔfG°, -936.3 kJ · mol−1
- ^ S°, 218.0 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°, -1403.7 kJ · mol−1
- ^ ΔfG°, -1295.7 kJ · mol−1
- ^ S°, 200.12 J · K−1 · mol−1
- ^ Cp°, 145.98 J · K−1 · mol−1
- ^ ΔfH°, -1385.91 kJ · mol−1
- ^ ΔfG°, -1294.30 kJ · mol−1
- ^ S°, 255.2 J · K−1 · mol−1
- ^ ΔfH°, -958.6 kJ · mol−1
- ^ ΔfH°, -989.5 kJ · mol−1
- ^ ΔfG°, -893.7 kJ · mol−1
- ^ S°, 130. J · K−1 · mol−1
- ^ ΔfH°, -2404.13 kJ · mol−1
- ^ ΔfH°, -225.35 kJ · mol−1
- ^ ΔfH°, -221.63 kJ · mol−1