19NaCl + 2K2Cr2O7 + 16H+ 🔥→ 3NaClO2 + 16Na+ + 4CrCl3 + 4KCl + 8H2O
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- Reaction of sodium chloride and potassium dichromate under acidic condition
- 19NaClSodium chloride + 2K2Cr2O7Potassium dichromate + 16H+Hydrogen ion3NaClO2Sodium chlorite + 16Na+Sodium ion + 4CrCl3Chromium(III) chloride + 4KClPotassium chloride + 8H2OWater🔥⟶
The reaction of sodium chloride, potassium dichromate, and hydrogen ion yields sodium chlorite, sodium ion, chromium(III) chloride, potassium chloride, and water (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 sodium chloride and potassium dichromate under acidic condition
- 19NaClSodium chloride + 2K2Cr2O7Potassium dichromate + 16H+Hydrogen ion3NaClO2Sodium chlorite + 16Na+Sodium ion + 4CrCl3Chromium(III) chloride + 4KClPotassium chloride + 8H2OWater🔥⟶
General equation
- Reaction of hardly oxidizable species and oxidizing species under acidic condition
- Hardly oxidizable speciesReducing agent + Oxidizing speciesOxidizing agent + H+Non-redox agent ⟶ ProductOxidation product + ProductReduction product + H2ONon-redox product
Oxidation state of each atom
- Reaction of sodium chloride and potassium dichromate under acidic condition
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| NaCl | Sodium chloride | 19 | Reducing | Hardly oxidizable |
| K2Cr2O7 | Potassium dichromate | 2 | Oxidizing | Oxidizing under acidic condition |
| H+ | Hydrogen ion | 16 | – | Hydrogen ion |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| NaClO2 | Sodium chlorite | 3 | Oxidized | – |
| Na+ | Sodium ion | 16 | – | – |
| CrCl3 | Chromium(III) chloride | 4 | Reduced | – |
| KCl | Potassium chloride | 4 | – | – |
| H2O | Water | 8 | – | Water |
Thermodynamic changes
Changes in standard condition
- Reaction of sodium chloride and potassium dichromate under acidic condition◆
ΔrG 780.8 kJ/mol K 0.16 × 10−136 pK 136.79
| 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 | 775.2 | 780.8 | −16.4 | – |
per 1 mol of | 40.80 | 41.09 | −0.863 | – |
per 1 mol of | 387.6 | 390.4 | −8.20 | – |
per 1 mol of Hydrogen ion | 48.45 | 48.80 | −1.02 | – |
per 1 mol of | 258.4 | 260.3 | −5.47 | – |
per 1 mol of Sodium ion | 48.45 | 48.80 | −1.02 | – |
per 1 mol of | 193.8 | 195.2 | −4.10 | – |
per 1 mol of | 193.8 | 195.2 | −4.10 | – |
per 1 mol of | 96.90 | 97.60 | −2.05 | – |
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 |
|---|---|---|---|---|
| NaCl (cr) | -411.153[1] | -384.138[1] | 72.13[1] | 50.50[1] |
| NaCl (g) | -176.65[1] | -196.66[1] | 229.81[1] | 35.77[1] |
| NaCl (ai) | -407.27[1] | -393.133[1] | 115.5[1] | -90.0[1] |
| K2Cr2O7 (cr) | -2061.5[1] | -1881.8[1] | 291.2[1] | 219.24[1] |
| K2Cr2O7 (ai) | -1994.9[1] | -1867.6[1] | 466.9[1] | – |
| H+ (g) | 1536.202[1] | – | – | – |
| H+ (ao) | 0[1] | 0[1] | 0[1] | 0[1] |
* (cr):Crystalline solid, (g):Gas, (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 |
|---|---|---|---|---|
| NaClO2 (cr) | -307.02[1] | – | – | – |
| NaClO2 (ai) | -306.7[1] | -244.7[1] | 160.2[1] | – |
| NaClO2 (cr) 3 hydrate | -1192.77[1] | – | – | – |
| Na+ (g) | 609.358[1] | – | – | – |
| Na+ (ao) | -240.12[1] | -261.905[1] | 59.0[1] | 46.4[1] |
| CrCl3 (cr) | -556.5[1] | -486.1[1] | 123.0[1] | 91.80[1] |
| KCl (cr) | -436.747[1] | -409.14[1] | 82.59[1] | 51.30[1] |
| KCl (g) | -214.14[1] | -233.0[1] | 239.10[1] | 36.48[1] |
| KCl (ai) | -419.53[1] | -414.49[1] | 159.0[1] | -114.6[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, (ao):Un-ionized aqueous solution, (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°, -411.153 kJ · mol−1
- ^ ΔfG°, -384.138 kJ · mol−1
- ^ S°, 72.13 J · K−1 · mol−1
- ^ Cp°, 50.50 J · K−1 · mol−1
- ^ ΔfH°, -176.65 kJ · mol−1
- ^ ΔfG°, -196.66 kJ · mol−1
- ^ S°, 229.81 J · K−1 · mol−1
- ^ Cp°, 35.77 J · K−1 · mol−1
- ^ ΔfH°, -407.27 kJ · mol−1
- ^ ΔfG°, -393.133 kJ · mol−1
- ^ S°, 115.5 J · K−1 · mol−1
- ^ Cp°, -90.0 J · K−1 · mol−1
- ^ ΔfH°, -2061.5 kJ · mol−1
- ^ ΔfG°, -1881.8 kJ · mol−1
- ^ S°, 291.2 J · K−1 · mol−1
- ^ Cp°, 219.24 J · K−1 · mol−1
- ^ ΔfH°, -1994.9 kJ · mol−1
- ^ ΔfG°, -1867.6 kJ · mol−1
- ^ S°, 466.9 J · K−1 · mol−1
- ^ ΔfH°, 1536.202 kJ · mol−1
- ^ ΔfH°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 0 J · K−1 · mol−1
- ^ Cp°, 0 J · K−1 · mol−1
- ^ ΔfH°, -307.02 kJ · mol−1
- ^ ΔfH°, -306.7 kJ · mol−1
- ^ ΔfG°, -244.7 kJ · mol−1
- ^ S°, 160.2 J · K−1 · mol−1
- ^ ΔfH°, -1192.77 kJ · mol−1
- ^ ΔfH°, 609.358 kJ · mol−1
- ^ ΔfH°, -240.12 kJ · mol−1
- ^ ΔfG°, -261.905 kJ · mol−1
- ^ S°, 59.0 J · K−1 · mol−1
- ^ Cp°, 46.4 J · K−1 · mol−1
- ^ ΔfH°, -556.5 kJ · mol−1
- ^ ΔfG°, -486.1 kJ · mol−1
- ^ S°, 123.0 J · K−1 · mol−1
- ^ Cp°, 91.80 J · K−1 · mol−1
- ^ ΔfH°, -436.747 kJ · mol−1
- ^ ΔfG°, -409.14 kJ · mol−1
- ^ S°, 82.59 J · K−1 · mol−1
- ^ Cp°, 51.30 J · K−1 · mol−1
- ^ ΔfH°, -214.14 kJ · mol−1
- ^ ΔfG°, -233.0 kJ · mol−1
- ^ S°, 239.10 J · K−1 · mol−1
- ^ Cp°, 36.48 J · K−1 · mol−1
- ^ ΔfH°, -419.53 kJ · mol−1
- ^ ΔfG°, -414.49 kJ · mol−1
- ^ S°, 159.0 J · K−1 · mol−1
- ^ Cp°, -114.6 J · K−1 · 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