Na2Cr2O7 + H2SeO4 → Na2SeO4 + 2CrO3 + H2O
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The reaction of sodium dichromate and selenic acid yields sodium selenate, chromium(VI) oxide, and water (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 sodium dichromate and selenic acid
General equation
- Salt of weak acidBrønsted base + Strong acidBrønsted acid ⟶ Salt of strong acidConjugate base + Acidic oxide + H2OConjugate acid
Oxidation state of each atom
- Reaction of sodium dichromate and selenic acid
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Na2Cr2O7 | Sodium dichromate | 1 | Brønsted base | Salt of weak acid |
| H2SeO4 | Selenic acid | 1 | Brønsted acid | Strong acid |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Na2SeO4 | Sodium selenate | 1 | Conjugate base | Salt of strong acid |
| CrO3 | Chromium(VI) oxide | 2 | – | Acidic oxide |
| H2O | Water | 1 | Conjugate acid | Water |
Thermodynamic changes
Changes in aqueous solution
- Reaction of sodium dichromate and selenic acid
| 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 | −43.5 | – | – | – |
per 1 mol of | −43.5 | – | – | – |
per 1 mol of | −43.5 | – | – | – |
per 1 mol of | −43.5 | – | – | – |
per 1 mol of | −21.8 | – | – | – |
per 1 mol of | −43.5 | – | – | – |
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 |
|---|---|---|---|---|
| Na2Cr2O7 (cr) | -1978.6[1] | – | – | – |
| Na2Cr2O7 (ai) | -1970.7[1] | -1824.9[1] | 379.9[1] | – |
| Na2Cr2O7 (cr) 2 hydrate | -2574.8[1] | – | – | – |
| H2SeO4 (cr) | -530.1[1] | – | – | – |
| H2SeO4 (cr) 1 hydrate | -840.6[1] | – | – | – |
| H2SeO4 (l) 1 hydrate | -820.5[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 |
|---|---|---|---|---|
| Na2SeO4 (cr) | -1069.0[1] | – | – | – |
| Na2SeO4 (ai) | -1079.5[1] | -965.2[1] | 172.0[1] | – |
| Na2SeO4 (cr) 10 hydrate | -4006.6[1] | – | – | – |
| CrO3 (cr) | -589.5[1] | – | – | – |
| CrO3 (g) | -385.8[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, (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°, -1978.6 kJ · mol−1
- ^ ΔfH°, -1970.7 kJ · mol−1
- ^ ΔfG°, -1824.9 kJ · mol−1
- ^ S°, 379.9 J · K−1 · mol−1
- ^ ΔfH°, -2574.8 kJ · mol−1
- ^ ΔfH°, -530.1 kJ · mol−1
- ^ ΔfH°, -840.6 kJ · mol−1
- ^ ΔfH°, -820.5 kJ · mol−1
- ^ ΔfH°, -1069.0 kJ · mol−1
- ^ ΔfH°, -1079.5 kJ · mol−1
- ^ ΔfG°, -965.2 kJ · mol−1
- ^ S°, 172.0 J · K−1 · mol−1
- ^ ΔfH°, -4006.6 kJ · mol−1
- ^ ΔfH°, -589.5 kJ · mol−1
- ^ ΔfH°, -385.8 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