KNO2 + HBr → KBr + HNO2
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The reaction of potassium nitrite and hydrogen bromide yields potassium bromide 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 hydrogen bromide
General equation
- Salt of weak acidBrønsted base + Strong acidBrønsted acid ⟶ Salt of strong acidConjugate base + Weak acidConjugate acid
Oxidation state of each atom
- Reaction of potassium nitrite and hydrogen bromide
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KNO2 | Potassium nitrite | 1 | Brønsted base | Salt of weak acid |
| HBr | Hydrogen bromide | 1 | Brønsted acid | Strong acid |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KBr | Potassium bromide | 1 | Conjugate base | Salt of strong acid |
| HNO2 | Nitrous acid | 1 | Conjugate acid | Weak acid |
Thermodynamic changes
Changes in standard condition
- Reaction of potassium nitrite and hydrogen bromide◆
ΔrG −18.5 kJ/mol K 1.74 × 103 pK −3.24
| 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 | −14.7 | −18.5 | 12.6 | – |
per 1 mol of | −14.7 | −18.5 | 12.6 | – |
per 1 mol of | −14.7 | −18.5 | 12.6 | – |
per 1 mol of | −14.7 | −18.5 | 12.6 | – |
per 1 mol of | −14.7 | −18.5 | 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] | – |
| HBr (g) | -36.40[1] | -53.45[1] | 198.695[1] | 29.142[1] |
| HBr (ai) | -121.55[1] | -103.96[1] | 82.4[1] | -141.8[1] |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (g):Gas
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 |
|---|---|---|---|---|
| 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] |
| 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°, -36.40 kJ · mol−1
- ^ ΔfG°, -53.45 kJ · mol−1
- ^ S°, 198.695 J · K−1 · mol−1
- ^ Cp°, 29.142 J · K−1 · mol−1
- ^ ΔfH°, -121.55 kJ · mol−1
- ^ ΔfG°, -103.96 kJ · mol−1
- ^ S°, 82.4 J · K−1 · mol−1
- ^ Cp°, -141.8 J · K−1 · mol−1
- ^ 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°, -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