2KBr + Na2CrO4 💧→ K2CrO4↓ + 2NaBr
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The reaction of potassium bromide and sodium chromate yields potassium chromate and sodium bromide. This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Reaction of potassium bromide and sodium chromate
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 bromide and sodium chromate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KBr | Potassium bromide | 2 | Lewis acid | Very soluble in water |
| Na2CrO4 | Sodium chromate | 1 | 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 |
| NaBr | Sodium bromide | 2 | Non-redox product | – |
Thermodynamic changes
Changes in standard condition
- Reaction of potassium bromide and sodium chromate◆
ΔrG 2.6 kJ/mol K 0.35 × 100 pK 0.46
| 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 | 4.0 | 2.6 | 5.35 | 2.01 |
per 1 mol of | 2.0 | 1.3 | 2.67 | 1.00 |
per 1 mol of | 4.0 | 2.6 | 5.35 | 2.01 |
per 1 mol of | 4.0 | 2.6 | 5.35 | 2.01 |
per 1 mol of | 2.0 | 1.3 | 2.67 | 1.00 |
Changes in aqueous solution
- Reaction of potassium bromide and sodium chromate◆
ΔrG 0.04 kJ/mol K 0.98 × 100 pK 0.01
| 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 | −0.01 | 0.04 | 0.0 | – |
per 1 mol of | −0.00500 | 0.0200 | 0.0 | – |
per 1 mol of | −0.0100 | 0.0400 | 0.0 | – |
per 1 mol of | −0.0100 | 0.0400 | 0.0 | – |
per 1 mol of | −0.00500 | 0.0200 | 0.0 | – |
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 |
|---|---|---|---|---|
| KBr (cr) | -393.798[1] | -380.66[1] | 95.90[1] | 52.30[1] |
| KBr (g) | -180.08[1] | -212.96[1] | 250.52[1] | 36.920[1] |
| KBr (ai) | -373.92[1] | -387.23[1] | 184.9[1] | -120.1[1] |
| Na2CrO4 (cr) | -1342.2[1] | -1234.93[1] | 176.61[1] | 142.13[1] |
| Na2CrO4 (ai) | -1361.39[1] | -1251.58[1] | 168.2[1] | – |
| Na2CrO4 (cr) 4 hydrate | -2528.8[1] | – | – | – |
| Na2CrO4 (cr) 10 hydrate | -4281.1[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 |
|---|---|---|---|---|
| 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] | – |
| NaBr (cr) | -361.062[1] | -348.983[1] | 86.82[1] | 51.38[1] |
| NaBr (g) | -143.1[1] | -177.06[1] | 241.19[1] | 36.32[1] |
| NaBr (ai) | -361.665[1] | -365.849[1] | 141.4[1] | -95.4[1] |
| NaBr (cr) 2 hydrate | -951.94[1] | -828.29[1] | 179.1[1] | – |
* (cr):Crystalline solid, (ai):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)
- ^ ΔfH°, -393.798 kJ · mol−1
- ^ ΔfG°, -380.66 kJ · mol−1
- ^ S°, 95.90 J · K−1 · mol−1
- ^ Cp°, 52.30 J · K−1 · mol−1
- ^ ΔfH°, -180.08 kJ · mol−1
- ^ ΔfG°, -212.96 kJ · mol−1
- ^ S°, 250.52 J · K−1 · mol−1
- ^ Cp°, 36.920 J · K−1 · mol−1
- ^ ΔfH°, -373.92 kJ · mol−1
- ^ ΔfG°, -387.23 kJ · mol−1
- ^ S°, 184.9 J · K−1 · mol−1
- ^ Cp°, -120.1 J · K−1 · mol−1
- ^ ΔfH°, -1342.2 kJ · mol−1
- ^ ΔfG°, -1234.93 kJ · mol−1
- ^ S°, 176.61 J · K−1 · mol−1
- ^ Cp°, 142.13 J · K−1 · mol−1
- ^ ΔfH°, -1361.39 kJ · mol−1
- ^ ΔfG°, -1251.58 kJ · mol−1
- ^ S°, 168.2 J · K−1 · mol−1
- ^ ΔfH°, -2528.8 kJ · mol−1
- ^ ΔfH°, -4281.1 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°, -361.062 kJ · mol−1
- ^ ΔfG°, -348.983 kJ · mol−1
- ^ S°, 86.82 J · K−1 · mol−1
- ^ Cp°, 51.38 J · K−1 · mol−1
- ^ ΔfH°, -143.1 kJ · mol−1
- ^ ΔfG°, -177.06 kJ · mol−1
- ^ S°, 241.19 J · K−1 · mol−1
- ^ Cp°, 36.32 J · K−1 · mol−1
- ^ ΔfH°, -361.665 kJ · mol−1
- ^ ΔfG°, -365.849 kJ · mol−1
- ^ S°, 141.4 J · K−1 · mol−1
- ^ Cp°, -95.4 J · K−1 · mol−1
- ^ ΔfH°, -951.94 kJ · mol−1
- ^ ΔfG°, -828.29 kJ · mol−1
- ^ S°, 179.1 J · K−1 · mol−1