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Chemical reactions
5NH4SCN + 8KMnO4 → 3KNO3 + 8MnO2 + 5KSCN + 7H2O + 2NH3↑

5NH₄SCN + 8KMnO₄ → 3KNO₃ + 8MnO₂ + 5KSCN + 7H₂O + 2NH₃↑

Last updated: May 12, 2022

Reaction of ammonium thiocyanate and potassium permanganate: 5NH₄SCNAmmonium thiocyanate + 8KMnO₄Potassium permanganate
⟶
3KNO₃Potassium nitrate + 8MnO₂Manganese(IV) oxide + 5KSCNPotassium thiocyanate + 7H₂OWater + 2NH₃↑Ammonia

The reaction of ammonium thiocyanate and potassium permanganate yields potassium nitrate, manganese(IV) oxide, potassium thiocyanate, water, and ammonia (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 ammonium thiocyanate and potassium permanganate: 5NH₄SCNAmmonium thiocyanate + 8KMnO₄Potassium permanganate
⟶
3KNO₃Potassium nitrate + 8MnO₂Manganese(IV) oxide + 5KSCNPotassium thiocyanate + 7H₂OWater + 2NH₃↑Ammonia

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 ammonium thiocyanate and potassium permanganate

Reactants

Chemical formula	Name	Coefficient	Type	Type in general equation
NH₄SCN	Ammonium thiocyanate	5	Reducing	Reducing
KMnO₄	Potassium permanganate	8	Oxidizing	Oxidizing

Products

Chemical formula	Name	Coefficient	Type	Type in general equation
KNO₃	Potassium nitrate	3	Oxidized	–
MnO₂	Manganese(IV) oxide	8	Reduced	–
KSCN	Potassium thiocyanate	5	–	–
H₂O	Water	7	–	–
NH₃	Ammonia	2	–	–

Thermodynamic changes

Changes in standard condition (1)

Reaction of ammonium thiocyanate and potassium permanganate: 5NH₄SCNCrystalline solid + 8KMnO₄Crystalline solid
⟶
3KNO₃Crystalline solid + 8MnO₂Crystalline solid + 5KSCNCrystalline solid + 7H₂OLiquid + 2NH₃↑Gas

	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	−1646.9	–	–	–
per 1 mol of Ammonium thiocyanate	−329.38	–	–	–
per 1 mol of Potassium permanganate	−205.86	–	–	–
per 1 mol of Potassium nitrate	−548.97	–	–	–
per 1 mol of Manganese(IV) oxide	−205.86	–	–	–
per 1 mol of Potassium thiocyanate	−329.38	–	–	–
per 1 mol of Water	−235.27	–	–	–
per 1 mol of Ammonia	−823.45	–	–	–

Changes in standard condition (2)

Reaction of ammonium thiocyanate and potassium permanganate: 5NH₄SCNCrystalline solid + 8KMnO₄Crystalline solid
⟶
3KNO₃Crystalline solid + 8MnO₂Amorphous solidprecipitated + 5KSCNCrystalline solid + 7H₂OLiquid + 2NH₃↑Gas

	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	−1506.6	–	–	–
per 1 mol of Ammonium thiocyanate	−301.32	–	–	–
per 1 mol of Potassium permanganate	−188.32	–	–	–
per 1 mol of Potassium nitrate	−502.20	–	–	–
per 1 mol of Manganese(IV) oxide	−188.32	–	–	–
per 1 mol of Potassium thiocyanate	−301.32	–	–	–
per 1 mol of Water	−215.23	–	–	–
per 1 mol of Ammonia	−753.30	–	–	–

Changes in aqueous solution (1)

Reaction of ammonium thiocyanate and potassium permanganate ◆ Δ_rG −1773.3 kJ/mol K 4.66 × 10³¹⁰ pK −310.67: 5NH₄SCNIonized aqueous solution + 8KMnO₄Ionized aqueous solution
⟶
3KNO₃Ionized aqueous solution + 8MnO₂Crystalline solid + 5KSCNIonized aqueous solution + 7H₂OLiquid + 2NH₃↑Gas

	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	−1881.4	−1773.3	−358.2	1026.7
per 1 mol of Ammonium thiocyanate	−376.28	−354.66	−71.64	205.34
per 1 mol of Potassium permanganate	−235.18	−221.66	−44.77	128.34
per 1 mol of Potassium nitrate	−627.13	−591.10	−119.4	342.23
per 1 mol of Manganese(IV) oxide	−235.18	−221.66	−44.77	128.34
per 1 mol of Potassium thiocyanate	−376.28	−354.66	−71.64	205.34
per 1 mol of Water	−268.77	−253.33	−51.17	146.67
per 1 mol of Ammonia	−940.70	−886.65	−179.1	513.35

Changes in aqueous solution (2)

Reaction of ammonium thiocyanate and potassium permanganate ◆ Δ_rG −1793.4 kJ/mol K 1.55 × 10³¹⁴ pK −314.19: 5NH₄SCNIonized aqueous solution + 8KMnO₄Ionized aqueous solution
⟶
3KNO₃Ionized aqueous solution + 8MnO₂Crystalline solid + 5KSCNIonized aqueous solution + 7H₂OLiquid + 2NH₃↑Un-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	−1949.8	−1793.4	−520.5	–
per 1 mol of Ammonium thiocyanate	−389.96	−358.68	−104.1	–
per 1 mol of Potassium permanganate	−243.72	−224.18	−65.06	–
per 1 mol of Potassium nitrate	−649.93	−597.80	−173.5	–
per 1 mol of Manganese(IV) oxide	−243.72	−224.18	−65.06	–
per 1 mol of Potassium thiocyanate	−389.96	−358.68	−104.1	–
per 1 mol of Water	−278.54	−256.20	−74.36	–
per 1 mol of Ammonia	−974.90	−896.70	−260.3	–

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
NH₄SCN (cr)	-78.7^[1]	–	–	–
NH₄SCN (ai)	-56.07^[1]	13.40^[1]	257.7^[1]	39.7^[1]
KMnO₄ (cr)	-837.2^[1]	-737.6^[1]	171.71^[1]	117.57^[1]
KMnO₄ (ai)	-793.8^[1]	-730.5^[1]	293.7^[1]	-60.2^[1]

* (cr):Crystalline solid, (ai):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
KNO₃ (cr)	-494.63^[1]	-394.86^[1]	133.05^[1]	96.40^[1]
KNO₃ (ai)	-459.74^[1]	-394.53^[1]	248.9^[1]	-64.9^[1]
MnO₂ (cr)	-520.03^[1]	-465.14^[1]	53.05^[1]	54.14^[1]
MnO₂ (am) precipitated	-502.5^[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]
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]
NH₃ (g)	-46.11^[1]	-16.45^[1]	192.45^[1]	35.06^[1]
NH₃ (ao)	-80.29^[1]	-26.50^[1]	111.3^[1]	–

* (cr):Crystalline solid, (ai):Ionized aqueous solution, (am):Amorphous solid, (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)
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