POTASSIUM BIFLUORIDE KHF2

Properties potassium bifluoride KHF2:

White, stable in dry air and in vacuum. It melts without decomposition, on further heating decomposes. Readily soluble in water, the anion is partially decomposed, and due to protolysis of HF creates an acidic environment. Does not form сrystalline hydrates. Decomposed by concentrated acids, neutralized by alkalis.


Obtaining potassium bifluoride KHF2:

КОН(diluted) + HF(diluted) = KF + H2O,

КОН(conc.) + 2HF(conc.) = KHF2 + H2O.

K2CO3 + 2HF(conc.) = 2KF + H2O + CO2↑

K2CO3 + 4HF(conc.) = 2KHF2 + H2O + CO2↑.

KF + HF(conc.) = KHF2

KF + nHF(liquid) = KF·nHF↓, or K[F(HF)n] (n = 1/4).


Chemical reactions with potassium bifluoride KHF2:

KHF2 = KF + HF (310-400°C).

KHF2 (diluted) + 6H2O = [К(H2O)6]+ + HF2-

HF2 - ↔ HF + F -,

HF + H2O ↔ F - + H3O +

2KHF2 + H2SO4 (conc.) = K2SO4 + 4HF↑ (boiling).

KHF2 + КОH (conc.) = 2KF + H2O.

KHF2 + Ca(OH)2 (saturated) = КОH + H2O + CaF2↓.

KHF2 + H2SO4 + 2SO3 = 2 HSO3F + KHSO4 (normal temp., in oleum).

KHF2 (liquid) → Electrolysis → H2↑(cathode) + F2↑(anode) + KF.


 

Did you know?

Group 2 metals are known as alkaline earth metals.