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4NaCl + Co(NO3)2 + 2H2O 🔥→ 2NaNO2 + 2NaOH + 2Cl2↑ + Co(OH)2

4NaCl + Co(NO₃)₂ + 2H₂O 🔥→ 2NaNO₂ + 2NaOH + 2Cl₂↑ + Co(OH)₂

Last updated: May 12, 2022

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition: 4NaClSodium chloride + Co(NO₃)₂Cobalt(II) nitrate + 2H₂OWater
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2NaNO₂Sodium nitrite + 2NaOHSodium hydroxide + 2Cl₂↑Chlorine + Co(OH)₂Cobalt(II) hydroxide

The reaction of sodium chloride, cobalt(II) nitrate, and water yields sodium nitrite, sodium hydroxide, chlorine, and cobalt(II) hydroxide (Other reactions are here). This reaction is an oxidation-reduction reaction and is classified as follows:

Reaction of hardly oxidizable species and oxidizing species under neutral condition

Table of contents

Reaction data

Chemical equation

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition: 4NaClSodium chloride + Co(NO₃)₂Cobalt(II) nitrate + 2H₂OWater
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2NaNO₂Sodium nitrite + 2NaOHSodium hydroxide + 2Cl₂↑Chlorine + Co(OH)₂Cobalt(II) hydroxide

General equation

Reaction of hardly oxidizable species and oxidizing species under neutral condition: Hardly oxidizable speciesReducing agent + Oxidizing speciesOxidizing agent + H₂ONon-redox agent
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ProductOxidation product + ProductReduction product

Oxidation state of each atom

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition

Reactants

Chemical formula	Name	Coefficient	Type	Type in general equation
NaCl	Sodium chloride	4	Reducing	Hardly oxidizable
Co(NO₃)₂	Cobalt(II) nitrate	1	Oxidizing	Oxidizing
H₂O	Water	2	–	Water

Products

Chemical formula	Name	Coefficient	Type	Type in general equation
NaNO₂	Sodium nitrite	2	Reduced	–
NaOH	Sodium hydroxide	2	–	–
Cl₂	Chlorine	2	Oxidized	–
Co(OH)₂	Cobalt(II) hydroxide	1	–	–

Thermodynamic changes

Changes in standard condition (1)

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition: 4NaClCrystalline solid + Co(NO₃)₂Crystalline solid + 2H₂OLiquid
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2NaNO₂Crystalline solid + 2NaOHCrystalline solid + 2Cl₂↑Gas + Co(OH)₂Crystalline solidblue, precipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	–	–	–
per 1 mol of Sodium chloride	–	–	–	–
per 1 mol of Cobalt(II) nitrate	–	–	–	–
per 1 mol of Water	–	–	–	–
per 1 mol of Sodium nitrite	–	–	–	–
per 1 mol of Sodium hydroxide	–	–	–	–
per 1 mol of Chlorine	–	–	–	–
per 1 mol of Cobalt(II) hydroxide	–	–	–	–

Changes in standard condition (2)

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition: 4NaClCrystalline solid + Co(NO₃)₂Crystalline solid + 2H₂OLiquid
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2NaNO₂Crystalline solid + 2NaOHCrystalline solid + 2Cl₂↑Gas + Co(OH)₂Crystalline solidpink, precipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	528.6	–	–	–
per 1 mol of Sodium chloride	132.2	–	–	–
per 1 mol of Cobalt(II) nitrate	528.6	–	–	–
per 1 mol of Water	264.3	–	–	–
per 1 mol of Sodium nitrite	264.3	–	–	–
per 1 mol of Sodium hydroxide	264.3	–	–	–
per 1 mol of Chlorine	264.3	–	–	–
per 1 mol of Cobalt(II) hydroxide	528.6	–	–	–

Changes in standard condition (3)

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition: 4NaClCrystalline solid + Co(NO₃)₂Crystalline solid + 2H₂OLiquid
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2NaNO₂Crystalline solid + 2NaOHCrystalline solid + 2Cl₂↑Gas + Co(OH)₂Crystalline solidpink, precipitated, aged

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	–	–	–
per 1 mol of Sodium chloride	–	–	–	–
per 1 mol of Cobalt(II) nitrate	–	–	–	–
per 1 mol of Water	–	–	–	–
per 1 mol of Sodium nitrite	–	–	–	–
per 1 mol of Sodium hydroxide	–	–	–	–
per 1 mol of Chlorine	–	–	–	–
per 1 mol of Cobalt(II) hydroxide	–	–	–	–

Changes in aqueous solution (1)

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition ◆ Δ_rG 475.5 kJ/mol K 0.50 × 10⁻⁸³ pK 83.30: 4NaClIonized aqueous solution + Co(NO₃)₂Ionized aqueous solution + 2H₂OLiquid
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2NaNO₂Ionized aqueous solution + 2NaOHIonized aqueous solution + 2Cl₂↑Gas + Co(OH)₂Un-ionized aqueous solution

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	475.5	–	–
per 1 mol of Sodium chloride	–	118.9	–	–
per 1 mol of Cobalt(II) nitrate	–	475.5	–	–
per 1 mol of Water	–	237.8	–	–
per 1 mol of Sodium nitrite	–	237.8	–	–
per 1 mol of Sodium hydroxide	–	237.8	–	–
per 1 mol of Chlorine	–	237.8	–	–
per 1 mol of Cobalt(II) hydroxide	–	475.5	–	–

Changes in aqueous solution (2)

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition ◆ Δ_rG 447.1 kJ/mol K 0.47 × 10⁻⁷⁸ pK 78.33: 4NaClIonized aqueous solution + Co(NO₃)₂Ionized aqueous solution + 2H₂OLiquid
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2NaNO₂Ionized aqueous solution + 2NaOHIonized aqueous solution + 2Cl₂↑Gas + Co(OH)₂Crystalline solidblue, precipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	447.1	–	–
per 1 mol of Sodium chloride	–	111.8	–	–
per 1 mol of Cobalt(II) nitrate	–	447.1	–	–
per 1 mol of Water	–	223.6	–	–
per 1 mol of Sodium nitrite	–	223.6	–	–
per 1 mol of Sodium hydroxide	–	223.6	–	–
per 1 mol of Chlorine	–	223.6	–	–
per 1 mol of Cobalt(II) hydroxide	–	447.1	–	–

Changes in aqueous solution (3)

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition ◆ Δ_rG 442.9 kJ/mol K 0.26 × 10⁻⁷⁷ pK 77.59: 4NaClIonized aqueous solution + Co(NO₃)₂Ionized aqueous solution + 2H₂OLiquid
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2NaNO₂Ionized aqueous solution + 2NaOHIonized aqueous solution + 2Cl₂↑Gas + Co(OH)₂Crystalline solidpink, precipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	504.0	442.9	204	–
per 1 mol of Sodium chloride	126.0	110.7	51.0	–
per 1 mol of Cobalt(II) nitrate	504.0	442.9	204	–
per 1 mol of Water	252.0	221.4	102	–
per 1 mol of Sodium nitrite	252.0	221.4	102	–
per 1 mol of Sodium hydroxide	252.0	221.4	102	–
per 1 mol of Chlorine	252.0	221.4	102	–
per 1 mol of Cobalt(II) hydroxide	504.0	442.9	204	–

Changes in aqueous solution (4)

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition ◆ Δ_rG 439.1 kJ/mol K 0.12 × 10⁻⁷⁶ pK 76.93: 4NaClIonized aqueous solution + Co(NO₃)₂Ionized aqueous solution + 2H₂OLiquid
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2NaNO₂Ionized aqueous solution + 2NaOHIonized aqueous solution + 2Cl₂↑Gas + Co(OH)₂Crystalline solidpink, precipitated, aged

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	439.1	–	–
per 1 mol of Sodium chloride	–	109.8	–	–
per 1 mol of Cobalt(II) nitrate	–	439.1	–	–
per 1 mol of Water	–	219.6	–	–
per 1 mol of Sodium nitrite	–	219.6	–	–
per 1 mol of Sodium hydroxide	–	219.6	–	–
per 1 mol of Chlorine	–	219.6	–	–
per 1 mol of Cobalt(II) hydroxide	–	439.1	–	–

Changes in aqueous solution (5)

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition ◆ Δ_rG 489.4 kJ/mol K 0.18 × 10⁻⁸⁵ pK 85.74: 4NaClIonized aqueous solution + Co(NO₃)₂Ionized aqueous solution + 2H₂OLiquid
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2NaNO₂Ionized aqueous solution + 2NaOHIonized aqueous solution + 2Cl₂↑Un-ionized aqueous solution + Co(OH)₂Un-ionized aqueous solution

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	489.4	–	–
per 1 mol of Sodium chloride	–	122.3	–	–
per 1 mol of Cobalt(II) nitrate	–	489.4	–	–
per 1 mol of Water	–	244.7	–	–
per 1 mol of Sodium nitrite	–	244.7	–	–
per 1 mol of Sodium hydroxide	–	244.7	–	–
per 1 mol of Chlorine	–	244.7	–	–
per 1 mol of Cobalt(II) hydroxide	–	489.4	–	–

Changes in aqueous solution (6)

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition ◆ Δ_rG 461.0 kJ/mol K 0.17 × 10⁻⁸⁰ pK 80.76: 4NaClIonized aqueous solution + Co(NO₃)₂Ionized aqueous solution + 2H₂OLiquid
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2NaNO₂Ionized aqueous solution + 2NaOHIonized aqueous solution + 2Cl₂↑Un-ionized aqueous solution + Co(OH)₂Crystalline solidblue, precipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	461.0	–	–
per 1 mol of Sodium chloride	–	115.3	–	–
per 1 mol of Cobalt(II) nitrate	–	461.0	–	–
per 1 mol of Water	–	230.5	–	–
per 1 mol of Sodium nitrite	–	230.5	–	–
per 1 mol of Sodium hydroxide	–	230.5	–	–
per 1 mol of Chlorine	–	230.5	–	–
per 1 mol of Cobalt(II) hydroxide	–	461.0	–	–

Changes in aqueous solution (7)

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition ◆ Δ_rG 456.8 kJ/mol K 0.94 × 10⁻⁸⁰ pK 80.03: 4NaClIonized aqueous solution + Co(NO₃)₂Ionized aqueous solution + 2H₂OLiquid
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2NaNO₂Ionized aqueous solution + 2NaOHIonized aqueous solution + 2Cl₂↑Un-ionized aqueous solution + Co(OH)₂Crystalline solidpink, precipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	457.2	456.8	−1	–
per 1 mol of Sodium chloride	114.3	114.2	−0.3	–
per 1 mol of Cobalt(II) nitrate	457.2	456.8	−1	–
per 1 mol of Water	228.6	228.4	−0.5	–
per 1 mol of Sodium nitrite	228.6	228.4	−0.5	–
per 1 mol of Sodium hydroxide	228.6	228.4	−0.5	–
per 1 mol of Chlorine	228.6	228.4	−0.5	–
per 1 mol of Cobalt(II) hydroxide	457.2	456.8	−1	–

Changes in aqueous solution (8)

Reaction of sodium chloride and cobalt(II) nitrate under neutral condition ◆ Δ_rG 453.0 kJ/mol K 0.43 × 10⁻⁷⁹ pK 79.36: 4NaClIonized aqueous solution + Co(NO₃)₂Ionized aqueous solution + 2H₂OLiquid
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2NaNO₂Ionized aqueous solution + 2NaOHIonized aqueous solution + 2Cl₂↑Un-ionized aqueous solution + Co(OH)₂Crystalline solidpink, precipitated, aged

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	453.0	–	–
per 1 mol of Sodium chloride	–	113.3	–	–
per 1 mol of Cobalt(II) nitrate	–	453.0	–	–
per 1 mol of Water	–	226.5	–	–
per 1 mol of Sodium nitrite	–	226.5	–	–
per 1 mol of Sodium hydroxide	–	226.5	–	–
per 1 mol of Chlorine	–	226.5	–	–
per 1 mol of Cobalt(II) hydroxide	–	453.0	–	–

Thermodynamic data of reactants

Chemical formula	Standard enthalpy of formation Δ_fH° kJ · mol⁻¹	Standard Gibbs energy of formation Δ_fG° kJ · mol⁻¹	Standard molar entropy S° J · K⁻¹ · mol⁻¹	Standard molar heat capacity at constant pressure C_p° J · K⁻¹ · mol⁻¹
NaCl (cr)	-411.153^[1]	-384.138^[1]	72.13^[1]	50.50^[1]
NaCl (g)	-176.65^[1]	-196.66^[1]	229.81^[1]	35.77^[1]
NaCl (ai)	-407.27^[1]	-393.133^[1]	115.5^[1]	-90.0^[1]
Co(NO₃)₂ (cr)	-420.5^[1]	–	–	–
Co(NO₃)₂ (ai)	-472.8^[1]	-276.9^[1]	180^[1]	–
Co(NO₃)₂ (cr) 2 hydrate	-1021.7^[1]	–	–	–
Co(NO₃)₂ (cr) 3 hydrate	-1325.9^[1]	–	–	–
Co(NO₃)₂ (cr) 4 hydrate	-1630.5^[1]	–	–	–
Co(NO₃)₂ (cr) 6 hydrate	-2211.20^[1]	–	–	452^[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, (g):Gas, (ai):Ionized aqueous solution, (l):Liquid

Thermodynamic data of products

Chemical formula	Standard enthalpy of formation Δ_fH° kJ · mol⁻¹	Standard Gibbs energy of formation Δ_fG° kJ · mol⁻¹	Standard molar entropy S° J · K⁻¹ · mol⁻¹	Standard molar heat capacity at constant pressure C_p° J · K⁻¹ · mol⁻¹
NaNO₂ (cr)	-358.65^[1]	-284.55^[1]	103.8^[1]	–
NaNO₂ (ai)	-344.8^[1]	-294.1^[1]	182.0^[1]	-51.0^[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]	–
Cl₂ (g)	0^[1]	0^[1]	223.066^[1]	33.907^[1]
Cl₂ (ao)	-23.4^[1]	6.94^[1]	121^[1]	–
Co(OH)₂ (cr) blue, precipitated	–	-450.1^[1]	–	–
Co(OH)₂ (cr) pink, precipitated	-539.7^[1]	-454.3^[1]	79^[1]	–
Co(OH)₂ (cr) pink, precipitated, aged	–	-458.1^[1]	–	–
Co(OH)₂ (ai)	-518.0^[1]	-369.0^[1]	-134^[1]	–
Co(OH)₂ (ao)	–	-421.7^[1]	–	–

* (cr):Crystalline solid, (ai):Ionized aqueous solution, (g):Gas, (l):Liquid, (ao):Un-ionized aqueous solution

References

List of references

1
Janiel J. Reed (1989)
The NBS Tables of Chemical Thermodynamic Properties: Selected Values for Inorganic and C1 and C2 Organic Substances in SI Units
https://doi.org/10.18434/M32124
National Institute of Standards and Technology (NIST)
Citation list

Δ_rG	475.5 kJ/mol
K	0.50 × 10⁻⁸³
pK	83.30

Δ_rG	447.1 kJ/mol
K	0.47 × 10⁻⁷⁸
pK	78.33

Δ_rG	442.9 kJ/mol
K	0.26 × 10⁻⁷⁷
pK	77.59

Δ_rG	439.1 kJ/mol
K	0.12 × 10⁻⁷⁶
pK	76.93

4NaCl + Co(NO3)2 + 2H2O 🔥→ 2NaNO2 + 2NaOH + 2Cl2↑ + Co(OH)2

Reaction data

Chemical equation

General equation

Oxidation state of each atom

Reactants

Products

Thermodynamic changes

Changes in standard condition (1)

Changes in standard condition (2)

Changes in standard condition (3)

Changes in aqueous solution (1)

Changes in aqueous solution (2)

Changes in aqueous solution (3)

Changes in aqueous solution (4)

Changes in aqueous solution (5)

Changes in aqueous solution (6)

Changes in aqueous solution (7)

Changes in aqueous solution (8)

Thermodynamic data of reactants

Thermodynamic data of products

References

List of references

Related reactions

Reactions with same reactants

Related categories

Type of reaction

General equation

Reactant

Product

4NaCl + Co(NO₃)₂ + 2H₂O 🔥→ 2NaNO₂ + 2NaOH + 2Cl₂↑ + Co(OH)₂