KNCS - POTASSIUM THIOCYANATE

Properties of potassium thiocyanate:

White, melts without decomposition, but on further heating becomes blue due to decomposition. It is readily soluble in water with a strong endo-effect (without hydrolysis). Decomposed by concentrated acids. It reacts with typical oxidants. Participates in reactions of an exchange and complex formation.


Molar mass g/mol 97.18
Density g/cm3 1.886
Melting point °C 173.2
Boiling point °C 500

Methods for preparation of potassium thiocyanate:

NH4NCS(conc.) + KOH(conc.) = KNCS + NH3↑ + H2O (boiling).

KCN(diluted) + S = KNCS (boiling).


Chemical reactions with potassium thiocyanate:

KNCS = KCN + S (above 500° C).

KNCS • 0.5H2O↓ = KNCS(saturated) + 0.5H2O (to 6.8° C).

KNCS(diluted) + 6H2O = [K(H2O)6](+) + NCS(-) (pH = 7).

2KNCS(solid) + H2SO4(conc.) = 2HNCS↑ + K2SO4 (cold, vacuum).

KNCS(damp) + KHSO4(solid) = time = HNCS + K2SO4 (normal temp., vacuum).

2KNCS + 2H2SO4(diluted) + MnO2 = (SCN)2 + MnSO4 + 2H2O + K2SO4 (0° C).

2KNCS(solution) + I2 = 2KI + (SCN)2 (0° C).

KNCS + 10KOH(conc.) + 8KMnO4 = KOCN + 8K2MnO4 + K2SO4 + 5H2O.

KNCS(conc.) + KNO2 + H2SO4(diluted) = (NO)NCS + K2SO4 + H2O (0° C).

2KNCS + SnO2 = SnS + 2CO + N2 + K2S (450° C).

2KNCS + Pb(NO3)2 = Pb(NCS)2↓ + 2KNO3.

KNCS(diluted) + AgNO3 = AgNCS↓ + KNO3,

2KNCS(conc.) + AgNO3 = K[Ag(SCN)2] + KNO3.

KNCS(diluted) + 5H2O + FeCl3 = [Fe(H2O)5(-NCS)]Cl2(red) + KCl,

6KNCS(conc.) + FeCl3 = K3[Fe(NCS)6](red) + 3KCl.


 

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