2KNO2 + H2SO4 → K2SO4 + 2HNO2
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The reaction of potassium nitrite and sulfuric acid yields potassium sulfate and nitrous acid (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 nitrite and sulfuric acid
General equation
- Salt of weak acidBrønsted base + Strong acidBrønsted acid ⟶ Salt of strong acidConjugate base + Weak acidConjugate acid
- Salt of volatile acidBrønsted base + Nonvolatile acidBrønsted acid ⟶ Salt of non volatile acidConjugate base + Volatile acidConjugate acid
Oxidation state of each atom
- Reaction of potassium nitrite and sulfuric acid
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KNO2 | Potassium nitrite | 2 | Brønsted base | Salt of weak acid Salt of volatile acid |
| H2SO4 | Sulfuric acid | 1 | Brønsted acid | Strong acid Nonvolatile acid |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K2SO4 | Potassium sulfate | 1 | Conjugate base | Salt of strong acid Salt of non volatile acid |
| HNO2 | Nitrous acid | 2 | Conjugate acid | Weak acid Volatile acid |
Thermodynamic changes
Changes in standard condition
- Reaction of potassium nitrite and sulfuric acid◆
ΔrG −36.9 kJ/mol K 2.91 × 106 pK −6.46
| 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 | −29.4 | −36.9 | 25.2 | – |
per 1 mol of | −14.7 | −18.4 | 12.6 | – |
per 1 mol of | −29.4 | −36.9 | 25.2 | – |
per 1 mol of | −29.4 | −36.9 | 25.2 | – |
per 1 mol of | −14.7 | −18.4 | 12.6 | – |
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 |
|---|---|---|---|---|
| KNO2 (cr) rhombic | -369.82[1] | -306.55[1] | 152.09[1] | 107.40[1] |
| KNO2 (ai) | -356.9[1] | -315.4[1] | 225.5[1] | – |
| H2SO4 (cr) | – | – | – | – |
| H2SO4 (l) | -813.989[1] | -690.003[1] | 156.904[1] | 138.91[1] |
| H2SO4 (ai) | -909.27[1] | -744.53[1] | 20.1[1] | -293[1] |
| H2SO4 (l) 1 hydrate | -1127.621[1] | -950.383[1] | 211.54[1] | 214.85[1] |
| H2SO4 (l) 2 hydrate | -1427.100[1] | -1199.650[1] | 276.40[1] | 260.83[1] |
| H2SO4 (l) 3 hydrate | -1720.402[1] | -1443.980[1] | 345.39[1] | 318.95[1] |
| H2SO4 (l) 4 hydrate | -2011.199[1] | -1685.863[1] | 414.59[1] | 382.21[1] |
| H2SO4 (l) 6.5 hydrate | -2733.256[1] | -2285.734[1] | 587.89[1] | 570.28[1] |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (l):Liquid
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 |
|---|---|---|---|---|
| K2SO4 (cr) | -1437.79[1] | -1321.37[1] | 175.56[1] | 131.46[1] |
| K2SO4 (g) | -1096[1] | -1033[1] | 364[1] | 108.8[1] |
| K2SO4 (ai) | -1414.02[1] | -1311.07[1] | 225.1[1] | -251[1] |
| HNO2 (g) cis | -77.99[1] | -42.94[1] | 248.76[1] | 44.77[1] |
| HNO2 (g) trans | -80.12[1] | -45.24[1] | 249.22[1] | 46.07[1] |
| HNO2 (g) | -79.5[1] | -46.0[1] | 254.1[1] | 45.6[1] |
| HNO2 (ao) | -119.2[1] | -50.6[1] | 135.6[1] | – |
* (cr):Crystalline solid, (g):Gas, (ai):Ionized aqueous solution, (ao):Un-ionized 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°, -369.82 kJ · mol−1
- ^ ΔfG°, -306.55 kJ · mol−1
- ^ S°, 152.09 J · K−1 · mol−1
- ^ Cp°, 107.40 J · K−1 · mol−1
- ^ ΔfH°, -356.9 kJ · mol−1
- ^ ΔfG°, -315.4 kJ · mol−1
- ^ S°, 225.5 J · K−1 · mol−1
- ^ ΔfH°, -813.989 kJ · mol−1
- ^ ΔfG°, -690.003 kJ · mol−1
- ^ S°, 156.904 J · K−1 · mol−1
- ^ Cp°, 138.91 J · K−1 · mol−1
- ^ ΔfH°, -909.27 kJ · mol−1
- ^ ΔfG°, -744.53 kJ · mol−1
- ^ S°, 20.1 J · K−1 · mol−1
- ^ Cp°, -293. J · K−1 · mol−1
- ^ ΔfH°, -1127.621 kJ · mol−1
- ^ ΔfG°, -950.383 kJ · mol−1
- ^ S°, 211.54 J · K−1 · mol−1
- ^ Cp°, 214.85 J · K−1 · mol−1
- ^ ΔfH°, -1427.100 kJ · mol−1
- ^ ΔfG°, -1199.650 kJ · mol−1
- ^ S°, 276.40 J · K−1 · mol−1
- ^ Cp°, 260.83 J · K−1 · mol−1
- ^ ΔfH°, -1720.402 kJ · mol−1
- ^ ΔfG°, -1443.980 kJ · mol−1
- ^ S°, 345.39 J · K−1 · mol−1
- ^ Cp°, 318.95 J · K−1 · mol−1
- ^ ΔfH°, -2011.199 kJ · mol−1
- ^ ΔfG°, -1685.863 kJ · mol−1
- ^ S°, 414.59 J · K−1 · mol−1
- ^ Cp°, 382.21 J · K−1 · mol−1
- ^ ΔfH°, -2733.256 kJ · mol−1
- ^ ΔfG°, -2285.734 kJ · mol−1
- ^ S°, 587.89 J · K−1 · mol−1
- ^ Cp°, 570.28 J · K−1 · mol−1
- ^ ΔfH°, -1437.79 kJ · mol−1
- ^ ΔfG°, -1321.37 kJ · mol−1
- ^ S°, 175.56 J · K−1 · mol−1
- ^ Cp°, 131.46 J · K−1 · mol−1
- ^ ΔfH°, -1096. kJ · mol−1
- ^ ΔfG°, -1033. kJ · mol−1
- ^ S°, 364. J · K−1 · mol−1
- ^ Cp°, 108.8 J · K−1 · mol−1
- ^ ΔfH°, -1414.02 kJ · mol−1
- ^ ΔfG°, -1311.07 kJ · mol−1
- ^ S°, 225.1 J · K−1 · mol−1
- ^ Cp°, -251. J · K−1 · mol−1
- ^ ΔfH°, -77.99 kJ · mol−1
- ^ ΔfG°, -42.94 kJ · mol−1
- ^ S°, 248.76 J · K−1 · mol−1
- ^ Cp°, 44.77 J · K−1 · mol−1
- ^ ΔfH°, -80.12 kJ · mol−1
- ^ ΔfG°, -45.24 kJ · mol−1
- ^ S°, 249.22 J · K−1 · mol−1
- ^ Cp°, 46.07 J · K−1 · mol−1
- ^ ΔfH°, -79.5 kJ · mol−1
- ^ ΔfG°, -46.0 kJ · mol−1
- ^ S°, 254.1 J · K−1 · mol−1
- ^ Cp°, 45.6 J · K−1 · mol−1
- ^ ΔfH°, -119.2 kJ · mol−1
- ^ ΔfG°, -50.6 kJ · mol−1
- ^ S°, 135.6 J · K−1 · mol−1