4KI + 2AgNO3 + 4H+ → 4K+ + I2 + 2NO2↑ + 2AgI + 2H2O
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- Reaction of potassium iodide and silver(I) nitrate under acidic condition
- 4KIPotassium iodide + 2AgNO3Silver(I) nitrate + 4H+Hydrogen ion4K+Potassium ion + + 2NO2↑Nitrogen dioxide + 2AgISilver(I) iodide + 2H2OWater⟶
The reaction of potassium iodide, silver(I) nitrate, and hydrogen ion yields potassium ion, , nitrogen dioxide, silver(I) iodide, 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 potassium iodide and silver(I) nitrate under acidic condition
- 4KIPotassium iodide + 2AgNO3Silver(I) nitrate + 4H+Hydrogen ion4K+Potassium ion + + 2NO2↑Nitrogen dioxide + 2AgISilver(I) iodide + 2H2OWater⟶
General equation
- Reaction of oxidizable species and oxidizing species under acidic condition
- Oxidizable speciesReducing agent + Oxidizing speciesOxidizing agent + H+Non-redox agent ⟶ ProductOxidation product + ProductReduction product + H2ONon-redox product
Oxidation state of each atom
- Reaction of potassium iodide and silver(I) nitrate under acidic condition
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KI | Potassium iodide | 4 | Reducing | Oxidizable |
| AgNO3 | Silver(I) nitrate | 2 | Oxidizing | Oxidizing under acidic condition |
| H+ | Hydrogen ion | 4 | – | Hydrogen ion |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K+ | Potassium ion | 4 | – | – |
| 1 | Oxidized | – | ||
| NO2 | Nitrogen dioxide | 2 | Reduced | – |
| AgI | Silver(I) iodide | 2 | – | – |
| H2O | Water | 2 | – | Water |
Thermodynamic changes
Changes in standard condition (1)
- Reaction of potassium iodide and silver(I) nitrate under acidic condition◆
ΔrG −29.56 kJ/mol K 1.51 × 105 pK −5.18
| 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 | 42.4 | −29.56 | 241.7 | – |
per 1 mol of | 10.6 | −7.390 | 60.42 | – |
per 1 mol of | 21.2 | −14.78 | 120.8 | – |
per 1 mol of Hydrogen ion | 10.6 | −7.390 | 60.42 | – |
per 1 mol of Potassium ion | 10.6 | −7.390 | 60.42 | – |
| 42.4 | −29.56 | 241.7 | – | |
per 1 mol of | 21.2 | −14.78 | 120.8 | – |
per 1 mol of | 21.2 | −14.78 | 120.8 | – |
per 1 mol of | 21.2 | −14.78 | 120.8 | – |
Changes in standard condition (2)
- Reaction of potassium iodide and silver(I) nitrate under acidic condition◆
ΔrG −104.8 kJ/mol K 2.29 × 1018 pK −18.36
| 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 | – | −104.8 | – | – |
per 1 mol of | – | −26.20 | – | – |
per 1 mol of | – | −52.40 | – | – |
per 1 mol of Hydrogen ion | – | −26.20 | – | – |
per 1 mol of Potassium ion | – | −26.20 | – | – |
| – | −104.8 | – | – | |
per 1 mol of | – | −52.40 | – | – |
per 1 mol of | – | −52.40 | – | – |
per 1 mol of | – | −52.40 | – | – |
Changes in standard condition (3)
- Reaction of potassium iodide and silver(I) nitrate under acidic condition◆
ΔrG −32.90 kJ/mol K 5.81 × 105 pK −5.76
| 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 | – | −32.90 | – | – |
per 1 mol of | – | −8.225 | – | – |
per 1 mol of | – | −16.45 | – | – |
per 1 mol of Hydrogen ion | – | −8.225 | – | – |
per 1 mol of Potassium ion | – | −8.225 | – | – |
| – | −32.90 | – | – | |
per 1 mol of | – | −16.45 | – | – |
per 1 mol of | – | −16.45 | – | – |
per 1 mol of | – | −16.45 | – | – |
Changes in standard condition (4)
- Reaction of potassium iodide and silver(I) nitrate under acidic condition◆
ΔrG −108.1 kJ/mol K 8.68 × 1018 pK −18.94
| 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 | – | −108.1 | – | – |
per 1 mol of | – | −27.02 | – | – |
per 1 mol of | – | −54.05 | – | – |
per 1 mol of Hydrogen ion | – | −27.02 | – | – |
per 1 mol of Potassium ion | – | −27.02 | – | – |
| – | −108.1 | – | – | |
per 1 mol of | – | −54.05 | – | – |
per 1 mol of | – | −54.05 | – | – |
per 1 mol of | – | −54.05 | – | – |
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 |
|---|---|---|---|---|
| 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] |
| AgNO3 (cr) | -124.39[1] | -33.41[1] | 140.92[1] | 93.05[1] |
| AgNO3 (ai) | -101.80[1] | -34.16[1] | 219.2[1] | -64.9[1] |
| AgNO3 (ao) | – | -32.49[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 |
|---|---|---|---|---|
| K+ (g) | 514.26[1] | – | – | – |
| K+ (ao) | -252.38[1] | -283.27[1] | 102.5[1] | 21.8[1] |
| (cr) | 0[1] | 0[1] | 116.135[1] | 54.438[1] |
| (g) | 62.438[1] | 19.327[1] | 260.69[1] | 36.90[1] |
| (ao) | 22.6[1] | 16.40[1] | 137.2[1] | – |
| NO2 (g) | 33.18[1] | 51.31[1] | 240.06[1] | 37.20[1] |
| AgI (cr) | -61.84[1] | -66.19[1] | 115.5[1] | 56.82[1] |
| AgI (ai) | 50.38[1] | 25.52[1] | 184.1[1] | -120.5[1] |
| AgI (ao) | – | -12.1[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] |
* (g):Gas, (ao):Un-ionized aqueous solution, (cr):Crystalline solid, (ai):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°, -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°, -124.39 kJ · mol−1
- ^ ΔfG°, -33.41 kJ · mol−1
- ^ S°, 140.92 J · K−1 · mol−1
- ^ Cp°, 93.05 J · K−1 · mol−1
- ^ ΔfH°, -101.80 kJ · mol−1
- ^ ΔfG°, -34.16 kJ · mol−1
- ^ S°, 219.2 J · K−1 · mol−1
- ^ Cp°, -64.9 J · K−1 · mol−1
- ^ ΔfG°, -32.49 kJ · 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°, 514.26 kJ · mol−1
- ^ ΔfH°, -252.38 kJ · mol−1
- ^ ΔfG°, -283.27 kJ · mol−1
- ^ S°, 102.5 J · K−1 · mol−1
- ^ Cp°, 21.8 J · K−1 · mol−1
- ^ ΔfH°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 116.135 J · K−1 · mol−1
- ^ Cp°, 54.438 J · K−1 · mol−1
- ^ ΔfH°, 62.438 kJ · mol−1
- ^ ΔfG°, 19.327 kJ · mol−1
- ^ S°, 260.69 J · K−1 · mol−1
- ^ Cp°, 36.90 J · K−1 · mol−1
- ^ ΔfH°, 22.6 kJ · mol−1
- ^ ΔfG°, 16.40 kJ · mol−1
- ^ S°, 137.2 J · K−1 · mol−1
- ^ ΔfH°, 33.18 kJ · mol−1
- ^ ΔfG°, 51.31 kJ · mol−1
- ^ S°, 240.06 J · K−1 · mol−1
- ^ Cp°, 37.20 J · K−1 · mol−1
- ^ ΔfH°, -61.84 kJ · mol−1
- ^ ΔfG°, -66.19 kJ · mol−1
- ^ S°, 115.5 J · K−1 · mol−1
- ^ Cp°, 56.82 J · K−1 · mol−1
- ^ ΔfH°, 50.38 kJ · mol−1
- ^ ΔfG°, 25.52 kJ · mol−1
- ^ S°, 184.1 J · K−1 · mol−1
- ^ Cp°, -120.5 J · K−1 · mol−1
- ^ ΔfG°, -12.1 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