POLYSULFIDES OF POTASSIUM K2(Sn)

Properties of polysulfides of potassium K2(Sn):

A mixture of K2(Sn)(n = 2/6) has a yellow-brown color. All K2(Sn) - a very hard, melts - dark brown mobile liquid. Thermal stability decreases with increasing n. Readily soluble in water, hydrolyzed (on anion) is significantly weaker than K2S; solution has a yellow color. Oxidized in air, decomposed by acids. Possess by oxidative properties.

 

Obtaining polysulfides of potassium K2(Sn):

K2S (solution) + O2 → (air, time) → S(colloid), K2(Sn), K2SO3S.

K2S (solition) + (n-l)S = K2(Sn) [boiling]

K2S + S = K2(S2) [500° С]

K2S + 2S = K2(S3) [boiling in ethanol]

K2S + 3S = K2(S4) [250-300° С]

K2S + 4S = K2(S5) [175-220° С].

K2(S5) + S = K2(S6) [120-180° C].

 

Reactions with polysulfides of potassium K2(Sn):

K2(Sn) = K2S + (n - 1)S (t >600° С).

K2(Sn)[diluted] + 12H2O = 2[K(H2O)6]+ + Sn2-

Sn2- + H2O ↔ HSn- + ОH-; pKo = 7.70 (n = 4), 8,30 (n = 5).

K2(Sn) + 2HCl(diluted) = 2KCl + H2S↑ + (n - 1)S↓ (normal temp.)

K2(Sn) + 2HCl(conc.) = 2KCl + H2Sn (-15° С).

2K2(Sn) + 2H2O(cold) + O2 = nS(colloid) + 4KОH (on the light)

2K2(Sn)[saturated, hot] + 3O2 = 2K2SO3S + (2n - 4)S↓.

K2(Sn) + H2O + SO2 = K2SO3S + H2S↑ + (n - 2)S↓ (normal temp.).

K2(Sn) + SnS2 = K2[SnS3] + (n - 1 )S↓

3K2(Sn) + As2S3 = 2K3[AsS4]+ (3n - 5)S↓.

K2(S5) + S = K2(S6) [120-180° C].

 

Did you know?

Liquid air has a bluish tint, similar to water.