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Chemical reactions
2KSCN + 6O2 → K2SO3 + SO2 + N2O3 + 2CO2

2KSCN + 6O₂ → K₂SO₃ + SO₂ + N₂O₃ + 2CO₂

Last updated: June 13, 2022

Reaction of potassium thiocyanate and oxygen: 2KSCNPotassium thiocyanate + 6O₂Oxygen
⟶
K₂SO₃Potassium sulfite + SO₂Sulfur dioxide + N₂O₃Dinitrogen trioxide + 2CO₂Carbon dioxide

The reaction of potassium thiocyanate and oxygen yields potassium sulfite, sulfur dioxide, dinitrogen trioxide, and carbon dioxide (Other reactions are here). This reaction is an oxidation-reduction reaction and is classified as follows:

Reaction of reducing species and oxidizing species

Table of contents

Reaction data

Chemical equation

Reaction of potassium thiocyanate and oxygen: 2KSCNPotassium thiocyanate + 6O₂Oxygen
⟶
K₂SO₃Potassium sulfite + SO₂Sulfur dioxide + N₂O₃Dinitrogen trioxide + 2CO₂Carbon dioxide

General equation

Reaction of reducing species and oxidizing species: Reducing speciesReducing agent + Oxidizing speciesOxidizing agent
⟶
ProductOxidation product + ProductReduction product

Oxidation state of each atom

Reaction of potassium thiocyanate and oxygen

Reactants

Chemical formula	Name	Coefficient	Type	Type in general equation
KSCN	Potassium thiocyanate	2	Reducing	Reducing
O₂	Oxygen	6	Oxidizing	Oxidizing

Products

Chemical formula	Name	Coefficient	Type	Type in general equation
K₂SO₃	Potassium sulfite	1	Redoxed product	–
SO₂	Sulfur dioxide	1	Redoxed product	–
N₂O₃	Dinitrogen trioxide	1	Redoxed product	–
CO₂	Carbon dioxide	2	Reduced	–

Thermodynamic changes

Changes in standard condition

Reaction of potassium thiocyanate and oxygen: 2KSCNCrystalline solid + 6O₂Gas
⟶
K₂SO₃Crystalline solid + SO₂Gas + N₂O₃Gas + 2CO₂Gas

	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	−1725.3	–	–	–
per 1 mol of Potassium thiocyanate	−862.65	–	–	–
per 1 mol of Oxygen	−287.55	–	–	–
per 1 mol of Potassium sulfite	−1725.3	–	–	–
per 1 mol of Sulfur dioxide	−1725.3	–	–	–
per 1 mol of Dinitrogen trioxide	−1725.3	–	–	–
per 1 mol of Carbon dioxide	−862.65	–	–	–

Changes in aqueous solution (1)

Reaction of potassium thiocyanate and oxygen ◆ Δ_rG −1719.8 kJ/mol K 1.98 × 10³⁰¹ pK −301.30: 2KSCNIonized aqueous solution + 6O₂Un-ionized aqueous solution
⟶
K₂SO₃Ionized aqueous solution + SO₂Gas + N₂O₃Gas + 2CO₂Gas

	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	−1718.1	−1719.8	5	–
per 1 mol of Potassium thiocyanate	−859.05	−859.90	3	–
per 1 mol of Oxygen	−286.35	−286.63	0.8	–
per 1 mol of Potassium sulfite	−1718.1	−1719.8	5	–
per 1 mol of Sulfur dioxide	−1718.1	−1719.8	5	–
per 1 mol of Dinitrogen trioxide	−1718.1	−1719.8	5	–
per 1 mol of Carbon dioxide	−859.05	−859.90	3	–

Changes in aqueous solution (2)

Reaction of potassium thiocyanate and oxygen ◆ Δ_rG −1703.1 kJ/mol K 2.35 × 10²⁹⁸ pK −298.37: 2KSCNIonized aqueous solution + 6O₂Un-ionized aqueous solution
⟶
K₂SO₃Ionized aqueous solution + SO₂Gas + N₂O₃Gas + 2CO₂Un-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	−1758.7	−1703.1	−188	–
per 1 mol of Potassium thiocyanate	−879.35	−851.55	−94.0	–
per 1 mol of Oxygen	−293.12	−283.85	−31.3	–
per 1 mol of Potassium sulfite	−1758.7	−1703.1	−188	–
per 1 mol of Sulfur dioxide	−1758.7	−1703.1	−188	–
per 1 mol of Dinitrogen trioxide	−1758.7	−1703.1	−188	–
per 1 mol of Carbon dioxide	−879.35	−851.55	−94.0	–

Changes in aqueous solution (3)

Reaction of potassium thiocyanate and oxygen ◆ Δ_rG −1720.3 kJ/mol K 2.42 × 10³⁰¹ pK −301.38: 2KSCNIonized aqueous solution + 6O₂Un-ionized aqueous solution
⟶
K₂SO₃Ionized aqueous solution + SO₂Un-ionized aqueous solution + N₂O₃Gas + 2CO₂Gas

	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	−1744.3	−1720.3	−82	–
per 1 mol of Potassium thiocyanate	−872.15	−860.15	−41	–
per 1 mol of Oxygen	−290.72	−286.72	−14	–
per 1 mol of Potassium sulfite	−1744.3	−1720.3	−82	–
per 1 mol of Sulfur dioxide	−1744.3	−1720.3	−82	–
per 1 mol of Dinitrogen trioxide	−1744.3	−1720.3	−82	–
per 1 mol of Carbon dioxide	−872.15	−860.15	−41	–

Changes in aqueous solution (4)

Reaction of potassium thiocyanate and oxygen ◆ Δ_rG −1703.6 kJ/mol K 2.87 × 10²⁹⁸ pK −298.46: 2KSCNIonized aqueous solution + 6O₂Un-ionized aqueous solution
⟶
K₂SO₃Ionized aqueous solution + SO₂Un-ionized aqueous solution + N₂O₃Gas + 2CO₂Un-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	−1784.9	−1703.6	−274	–
per 1 mol of Potassium thiocyanate	−892.45	−851.80	−137	–
per 1 mol of Oxygen	−297.48	−283.93	−45.7	–
per 1 mol of Potassium sulfite	−1784.9	−1703.6	−274	–
per 1 mol of Sulfur dioxide	−1784.9	−1703.6	−274	–
per 1 mol of Dinitrogen trioxide	−1784.9	−1703.6	−274	–
per 1 mol of Carbon dioxide	−892.45	−851.80	−137	–

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
KSCN (cr)	-200.16^[1]	-178.31^[1]	124.26^[1]	88.53^[1]
KSCN (ai)	-175.94^[1]	-190.56^[1]	246.9^[1]	-18.4^[1]
O₂ (g)	0^[1]	0^[1]	205.138^[1]	29.355^[1]
O₂ (ao)	-11.7^[1]	16.4^[1]	110.9^[1]	–

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

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
K₂SO₃ (cr)	-1125.5^[1]	–	–	–
K₂SO₃ (ai)	-1140.1^[1]	-1053.1^[1]	176^[1]	–
SO₂ (l)	-320.5^[1]	–	–	–
SO₂ (g)	-296.830^[1]	-300.194^[1]	248.22^[1]	39.87^[1]
SO₂ (ao)	-322.980^[1]	-300.676^[1]	161.9^[1]	–
N₂O₃ (l)	50.29^[1]	–	–	–
N₂O₃ (g)	83.72^[1]	139.46^[1]	312.28^[1]	65.61^[1]
CO₂ (g)	-393.509^[1]	-394.359^[1]	213.74^[1]	37.11^[1]
CO₂ (ao)	-413.80^[1]	-385.98^[1]	117.6^[1]	–

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