2KHS + 2CaCr2O7 💧→ K2CrO4↓ + 2CaS↓ + 3CrO3 + H2O
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The reaction of potassium hydrogensulfide and calcium dichromate yields potassium chromate, calcium sulfide, chromium(VI) oxide, and water (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 hydrogensulfide and calcium 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 hydrogensulfide and calcium dichromate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KHS | Potassium hydrogensulfide | 2 | Lewis acid | Soluble in water |
| CaCr2O7 | Calcium dichromate | 2 | Lewis base | Very soluble in water |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K2CrO4 | Potassium chromate | 1 | Lewis conjugate | Insoluble in water |
| CaS | Calcium sulfide | 2 | Lewis conjugate | Slightly soluble in water |
| CrO3 | Chromium(VI) oxide | 3 | Non-redox product | – |
| H2O | Water | 1 | Non-redox product | – |
Thermodynamic changes
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 |
|---|---|---|---|---|
| KHS (cr) | -265.10[1] | – | – | 75.31[1] |
| KHS (ai) | -269.9[1] | -271.19[1] | 165.3[1] | – |
| KHS (cr) 0.25 hydrate | -337.2[1] | – | – | – |
| CaCr2O7 | – | – | – | – |
* (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] | – |
| CaS (cr) | -482.4[1] | -477.4[1] | 56.5[1] | 47.40[1] |
| CaS (g) | – | – | – | – |
| CrO3 (cr) | -589.5[1] | – | – | – |
| CrO3 (g) | -385.8[1] | – | – | – |
| H2O (cr) | – | – | – | – |
| H2O (l) | -285.830[1] | -237.129[1] | 69.91[1] | 75.291[1] |
| H2O (g) | -241.818[1] | -228.572[1] | 188.825[1] | 33.577[1] |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (g):Gas, (l):Liquid
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°, -265.10 kJ · mol−1
- ^ Cp°, 75.31 J · K−1 · mol−1
- ^ ΔfH°, -269.9 kJ · mol−1
- ^ ΔfG°, -271.19 kJ · mol−1
- ^ S°, 165.3 J · K−1 · mol−1
- ^ ΔfH°, -337.2 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°, -482.4 kJ · mol−1
- ^ ΔfG°, -477.4 kJ · mol−1
- ^ S°, 56.5 J · K−1 · mol−1
- ^ Cp°, 47.40 J · K−1 · mol−1
- ^ ΔfH°, -589.5 kJ · mol−1
- ^ ΔfH°, -385.8 kJ · mol−1
- ^ ΔfH°, -285.830 kJ · mol−1
- ^ ΔfG°, -237.129 kJ · mol−1
- ^ S°, 69.91 J · K−1 · mol−1
- ^ Cp°, 75.291 J · K−1 · mol−1
- ^ ΔfH°, -241.818 kJ · mol−1
- ^ ΔfG°, -228.572 kJ · mol−1
- ^ S°, 188.825 J · K−1 · mol−1
- ^ Cp°, 33.577 J · K−1 · mol−1