POTASSIUM SULFIDE K2S

Properties of potassium sulfide K2S:

White, melts without decomposition. Thermally stable. Anhydrous powdered K2S pyrophoric in dry air. Readily soluble in water (strong hydrolysis on the anion). Reactive, moist oxidized by atmospheric oxygen, joins sulfur. Decomposes by acids. Typical reducing agent.


Obtaining potassium sulfide K2S:

2K + E = K2E (100-200°C; E = S, Se, Те).

K2SO4 + 4H2 = K2S + 4H2O (600° С, catalyst Fe2O3).

K2SO4 + 4 C (coke) = K2S + 4CO (900° C).


Chemical reactions with potassium sulfide K2S:

K2S - 5H2O = K2S + 5H2O (150° С).

K2S (diluted) + 12 H2O = 2[K(H2O)6]+ + S-2

S2- + H2O ↔ HS- + OH-.

K2S + 2 HCl (diluted) = 2 KCl + H2S↑.

K2S + 3 H2SO4 (conc.) = 2 KHSO4 + SO2↑ S2↓ + H2O.

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

K2S (solid) + 2O2 = K2SO4 (t > 500° С).

K2S (solution) + (n-1) 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].

K2S + H2S (saturated) = 2 KHS.


 

Did you know?

The rarest naturally-occurring element in the earth's crust may be astatine. The entire crust appears to contain about 28 g of the element.