NaOH → Na+ + OH−
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- Electrolytic dissociation of sodium hydroxide
Electrolytic dissociation of sodium hydroxide yields sodium ion and hydroxide ion. This reaction is an acid-base reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Electrolytic dissociation of sodium hydroxide
General equation
- Electrolytic dissociation of hydroxide base
- Hydroxide baseBrønsted base ⟶ CationConjugate acid + OH−
Oxidation state of each atom
- Electrolytic dissociation of sodium hydroxide
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| NaOH | Sodium hydroxide | 1 | Brønsted base | Hydroxide base |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Na+ | Sodium ion | 1 | Conjugate acid | Cation |
| OH− | Hydroxide ion | 1 | – | Hydroxide ion |
Thermodynamic changes
Changes in standard condition
- Electrolytic dissociation of sodium hydroxide◆
ΔrG −39.655 kJ/mol K 8.86 × 106 pK −6.95
| 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 | −44.51 | −39.655 | −16.2 | −161.6 |
per 1 mol of | −44.51 | −39.655 | −16.2 | −161.6 |
per 1 mol of Sodium ion | −44.51 | −39.655 | −16.2 | −161.6 |
per 1 mol of Hydroxide ion | −44.51 | −39.655 | −16.2 | −161.6 |
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 |
|---|---|---|---|---|
| NaOH (cr) | -425.609[1] | -379.494[1] | 64.455[1] | 59.54[1] |
| NaOH (g) | -207.1[1] | -210.0[1] | 228.43[1] | 48.37[1] |
| NaOH (ai) | -470.114[1] | -419.150[1] | 48.1[1] | -102.1[1] |
| NaOH (cr) 1 hydrate | -734.543[1] | -629.338[1] | 99.50[1] | 90.17[1] |
| NaOH (l) 2 hydrate | -1019.076[1] | -873.091[1] | 195.979[1] | 239.41[1] |
| NaOH (l) 3.5 hydrate | -1459.798[1] | -1236.356[1] | 286.089[1] | 354.43[1] |
| NaOH (l) 4 hydrate | -1605.15[1] | -1356.64[1] | 318.70[1] | – |
| NaOH (l) 5 hydrate | -1894.31[1] | -1596.34[1] | 386.06[1] | – |
| NaOH (l) 7 hydrate | -2469.02[1] | -2073.80[1] | 526.31[1] | – |
* (cr):Crystalline solid, (g):Gas, (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 |
|---|---|---|---|---|
| Na+ (g) | 609.358[1] | – | – | – |
| Na+ (ao) | -240.12[1] | -261.905[1] | 59.0[1] | 46.4[1] |
| OH− (g) | -143.5[1] | – | – | – |
| OH− (ao) | -229.994[1] | -157.244[1] | -10.75[1] | -148.5[1] |
* (g):Gas, (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°, -425.609 kJ · mol−1
- ^ ΔfG°, -379.494 kJ · mol−1
- ^ S°, 64.455 J · K−1 · mol−1
- ^ Cp°, 59.54 J · K−1 · mol−1
- ^ ΔfH°, -207.1 kJ · mol−1
- ^ ΔfG°, -210.0 kJ · mol−1
- ^ S°, 228.43 J · K−1 · mol−1
- ^ Cp°, 48.37 J · K−1 · mol−1
- ^ ΔfH°, -470.114 kJ · mol−1
- ^ ΔfG°, -419.150 kJ · mol−1
- ^ S°, 48.1 J · K−1 · mol−1
- ^ Cp°, -102.1 J · K−1 · mol−1
- ^ ΔfH°, -734.543 kJ · mol−1
- ^ ΔfG°, -629.338 kJ · mol−1
- ^ S°, 99.50 J · K−1 · mol−1
- ^ Cp°, 90.17 J · K−1 · mol−1
- ^ ΔfH°, -1019.076 kJ · mol−1
- ^ ΔfG°, -873.091 kJ · mol−1
- ^ S°, 195.979 J · K−1 · mol−1
- ^ Cp°, 239.41 J · K−1 · mol−1
- ^ ΔfH°, -1459.798 kJ · mol−1
- ^ ΔfG°, -1236.356 kJ · mol−1
- ^ S°, 286.089 J · K−1 · mol−1
- ^ Cp°, 354.43 J · K−1 · mol−1
- ^ ΔfH°, -1605.15 kJ · mol−1
- ^ ΔfG°, -1356.64 kJ · mol−1
- ^ S°, 318.70 J · K−1 · mol−1
- ^ ΔfH°, -1894.31 kJ · mol−1
- ^ ΔfG°, -1596.34 kJ · mol−1
- ^ S°, 386.06 J · K−1 · mol−1
- ^ ΔfH°, -2469.02 kJ · mol−1
- ^ ΔfG°, -2073.80 kJ · mol−1
- ^ S°, 526.31 J · K−1 · 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°, -143.5 kJ · mol−1
- ^ ΔfH°, -229.994 kJ · mol−1
- ^ ΔfG°, -157.244 kJ · mol−1
- ^ S°, -10.75 J · K−1 · mol−1
- ^ Cp°, -148.5 J · K−1 · mol−1