کل واکنشهای عنصر پتاسیم
POTASSIUM - K
Properties of Potassium :
An alkali metal. A silvery-white (in a thin layer - with a purple tinge), soft, low melting. Blue-green pairs of potassium consist from atoms of K (mainly) and K2 molecules. Chemically dissolves in liquid ammonia (dark blue solution), in the molten hydroxide potassium. It is extremely reactive, the strongest reducing agent, reacts with O2 of air, water (there is ignition of the evolved hydrogen), dilute acids, non-metals, ammonia, hydrogen sulfide. Practically does not react with nitrogen (in contrast to Li and Na). It is well preserved under a layer of gasoline or kerosene. With the mercury forms an amalgam. Do not fused with Li, Mg, Zn, Cd, Al and Ga. Forms intermetallic compounds with Na, Tl, Sn, Pb and Bi. Colors the flame of a gas burner in a purple color. The fifth element of the spread in nature.
| Molar mass | g/mol | 39.098 |
| Density in solid state | g/cm3 | 0.8629 |
| Melting point | °C | 63.51 |
| Boiling point | °C | 760 |
Obtaining metallic potassium:
2 KH = 2K + H2 (400° C, vacuum).
4 KOH (liquid) → Electrolysis 4 K (cathode) + O2 ↑(anode) + 2 H2O.
2 KCl (liquid) → Electrolysis 2 K (cathode) + Cl2 ↑(anode).
2 KCl + 2H2O → Electrolysis H2↑(cathode) + Cl2 ↑(anode) + 2KOH
2 KCl (melt) (on Hg-cathode)→ Electrolysis 2 K(cathode) + Cl2 ↑(anode).
Chemical reactions with metallic potassium:
2 K + 2H2O = 2 KOH + H2↑.
2 K + 2 HCl (diluted) = 2KCl + H2↑.
8 K + 6 H2SO4 (diluted) = 4 K2SO4 + SO2 + S ↓ + 6 H2O (impurityH2S)
21 K + 26 HNO3 (diluted) = 21 KNO3 + NO ↑ + N2O ↑ + N2 ↑ + 13H2O.
2 K + 2 KOH = 2K2O + H2 (450° C).
2 K + H2 = 2 KH (200—350° C).
K + O2 (air) = KO2 (burning, impurity of K2O2)
K →( O2 ) K2O2↓ →O2, (time) KO2↓ (- 50° C, in the liquid NH3).
4 K + O2 + 2 H2O = 4KOH.
2 K + E2 = 2 KE (normal temp.; E = F, Cl, Вr, I).
2 K + E = K2E (100—200°C ;E = S, Se, ТE).
З K + Р (red) = K3P (green) [200° C, in the atmosphere Аr].
2 K + 2 H2S (saturated)= 2 KHS ↓ + H2↑ (in benzene).
2 K + 2 NH3 (gas) = 2KNH2 + H2 (65—105° C).
K + 6 NH3 (liquid) = [K(NH3)6] (dark-blue) [- 50° C]
[K(NH3)6] + n NH3 (liquid) ↔ [K(NH3)6]+ + E-nNH3.
POTASSIUM AMIDE KNH2
Properties of Potassium amide KNH2 :
White, melts without decomposition, decomposes on further heating. Oxidized in air, and turn yellow (the products are unknown). Not soluble in liquid ammonia. Hydrolyzed by water, reacts with acids.
| Molar mass | g/mol | 55.12 |
| Melting point | °C | 338 |
Obtaining potassium amide KNH2:
2K + 2 NH3 (gas) = 2 KNH2 + H2 (65—105° С).
KH + NH3 (gas) = KNH2 + H2 (300° С).
K2O + NH3 (liquid) →(time) KNH2↓ + KOH (- 50° С).
Chemical reactions with potassium amide:
6 KNH2 = 6K + 4NH3 + N2 (600—700° С).
KNH2 + 2 H2O (cold) = KOH + NH3-H2O
KNH2 + H2O (hot) = KOH + NH3↑.
KNH2 + 2 HCl (diluted) = KCl + NH4Cl.
2 KNH2 + 2 HNO3 = KN3 + KNO3 + 3H2O (boiling).
KNH2 + С (coke) = KCN + H2 (500—600° С).
KNH2 + NH4Cl = 2NH3 + KCl (-40° С, in the liquid of NH3).
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, KOH)→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] + 12H2О = 2[K(H2О)6]+ + Sn2-
Sn2- + H2О ↔ 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) + 2H2О(cold) + O2 = nS(colloid) + 4KОH (on the light)
2K2(Sn)[saturated, hot] + 3О2 = 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].
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]+ + S2-
S2- + H2O ↔ HS- + OH-.
K2S + 2 HCl (diluted) = 2 KCl + H2S↑.
K2S + 3 H2SO4 (conc.) = 2 KHSO4 + SO2↑ S2↓ + H2O.
K2S (solution) -KOH → 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.
POTASSIUM IODIDE KI
Properties of potassium iodide KI:
White, when stored on the light turn yellow. Readily soluble in water (without hydrolysis). Does not form Crystalline hydrates. Typical reducing agent. An aqueous solution of KI chemically dissolves potassium iodide by complexation.
| Molar mass | g/mol | 166.00 |
| Density | g/cm3 | 3.115 |
| Melting point | °C | 681 |
Obtaining potassium iodide KI:
2 K + E2 = 2KE (normal temp.; E = F, Cl, Вr, I).
2 KOH + FeI2 = 2 KI + Fe(OH)2↓ (in the atmosphere N2)
2 KOH (diluted) + 2 AgNO3 = Ag2O↓ + H2O + 2 KNO3.
KIO3 + 3 H2O2 = KI + 3O2↑ + 3 H2O (in diluted HNO3).
Chemical reactions with potassium iodide KI:
KI (diluted) + 6H2O = [K(H2O)6](+) + I(-) (PH 7).
8 KI (solid) + 9 H2SO4 (conc.) = 4 I2↓ + H2S↑ + 4H2O + 8 KHSO4 (30—50° C).
KI + 2 H2O + O2 →(time) 4 KOH + I2↓ + K[I(I)2] (normal temp., on the light)
4 KI + 4 HCl (diluted) + O2 = 2 I2↓ + 4 KCl + 2H2O (normal temp., on the light).
2 KI + E2 = 2KE + I2↓ (E = Cl, Br).
KI + 3 H2O + 3 Cl2 (gas) = HIO3 + KCl + 5 HCl
KI (conc.) + 6 KOH(conc.) + 3 Cl2 (gas) = KIO3↓ + 6 KCl + 3H2O.
KI (solition) + I2 = K[I(I)2](solution) (yellow).
10 KI + 8 H2SO4 (diluted) + 2 KMnO4 = 5I2↓ + 2 MnSO4 + 8 H2O + 6 K2SO4
6 KI + 7 H2SO4 (diluted) + K2Cr2O7 = Cr2(SO4)3 + 3 I2↓ + 7 H2O + 4 K2SO4.
2 KI + H2SO4 (diluted.) + H2O2 = I2↓ + K2SO4 + 2H2O
2 KI + 2 H2SO4 (diluted) + 2 KNO2 = 2 K2SO4 + I2↓ + 2NO ↑ + 2H2O.
2 KI + Fe2(SO4)3 = I2↓ + 2 FeSO4 + K2SO4 (in the diluted H2SO4).
2 KI + 2 CuSO4 + K2SO3 + H2O=2 CuI↓ + 2 K2SO4 + H2SO4 (in the dark).
KI + 3 H2O → Electrolysis 3 H2↑ (cathode) + KIO3 (anode).
POTASSIUM BROMIDE KBr
Properties of potassium bromide KBr:
White, melts without decomposition. Readily soluble in water (without hydrolysis). Does not form сrystalline hydrates. Is not soluble in concentrated hydrobromic acid. Typical reducing agent.
Obtaining potassium bromide KBr:
2 K + E2 = 2KE (normal temp.; E = F, Cl, Br, I).
2 KI + E2 = 2KE + I2↓ (E = Cl, Br).
2 KBrO3 = 2 KBr + 3 O2 (t>434°C).
Chemical reactions with potassium bromide KBr:
KBr (diluted) + 6H2O = [K(H2O)6]+ + Br- (pH 7).
2 KBr (solid) + H2SO4 (10-50% conc., cold) = K2SO4 + 2 HBr
2 KBr (solid) + 3 H2SO4 (conc.>50% , hot) = 2 KHSO4 + Br2↑ + SO2↑ + 2H2O.
2 KBr + Cl2 = 2 KCl + Br2↑ (boiling).
5 KBr + 3 H2SO4 (diluted) + KBrO3 = 3 Br2 + 3 K2SO4 + 3H2O
2 KBr + 2 H2SO4 (conc.) + MnO2 = Br2 + K2SO4 + MnSO4 + 2 H2O (boiling).
KBr + 3 H2O (hot) → Electrolysis → 3H2↑ (cathode) + KBrO3(anode).
POTASSIUM CHLORIDE KCl
Properties of potassium chloride KCl:
Sylvite. White, melts and boils without decomposition. Moderately soluble in water (without hydrolysis). Does not form сrystalline hydrates. Poorly soluble in concentrated hydrochloric acid, liquid ammonia. A weak reducing agent.Participates in exchange reactions. Main part (along with NaCl) of natural deposits of sylvite.
Obtaining potassium cloride KCl:
2 K + 2 НСl (diluted) = 2 KСl + H2↑.
2 K + E2 = 2KE (normal temp.; E = F, Cl, Вr, I).
KОН + НСl (diluted) = KСl + H2O
KОН + HNO3 (diluted) = KNO3 + H2O.
KОН (conc.) + NH4Cl (conc.) = KCl + NH3↑ + H2O (boiling).
K2CO3 + 2 HCl (diluted) = 2 KCl + CO2↑ + H2O.
K2SO4 + BaE2 = BaSO4 ↓ + 2KE (E = Сl-, OH-).
Chemical reactions with potassium cloride KCl:
KCl (diluted) + 6 H2O = [K(H2O)6](+) + Cl(-) (pH 7).
2 KCl (solid) + H2SO4 (conc.) = K2SO4 + 2 HCl↑ (boiling).
KCl + KHSO4 = K2SO4 + HCl (450-700°C).
10 KCl (solid) + 8 H2SO4 (conc., hot) + 2 KMnO4 = 5 Cl2↑ + 2 MnSO4 + 6 K2SO4 + 8H2O.
KСl (conc.) + NaClO4 (saturated) = KClO4 ↓ + NaCl (10°C).
2 KCl (liquid) → Electrolysis 2 K (cathode) + Cl2↑ (anode).
2 KCl + 2H2O → Electrolysis H2 ↑ (cathode) + Cl2↑ (anode) + 2KОН
2 KCl (melt) (on Hg-cathode) → Electrolysis 2 K (cathode) + Cl2↑(anode).
KCl + 3H2O → Electrolysis 3 H2↑ (cathode) + KClO3(anode) [40-60°C].
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.
POTASSIUM FLUORIDE KF
Properties potassium fluoride KF:
White, melts without decomposition. Readily soluble in water (hydrolysis on the anion). Decomposes by acids.
| Molar mass | g/mol | 58.10 |
| Density | g/cm3 | 2.48 |
| Melting point | °C | 857 |
Obtaining potassium fluoride KF:
2K + E2 = 2KE (normal temp.; E = F, Cl, Вr, I).
KОН (diluted) + HF(diluted) = KF + H2O
KОН (conc.) + 2HF(conc.) = KHF2 + H2O.
K2CO3 + 2HF(diluted) = 2KF + H2O + CO2↑,
K2CO3 + 4HF(conc.) = 2KHF2 + H2O + CO2↑.
KHF2 = KF + HF (310-400°C).
KHF2 (liquid) → Electrolysis → H2↑ (cathode) + F2↑ (anode) + KF.
Chemical reactions with potassium fluoride KF:
KF·2H2O = KF + 2 H2O (350°C).
KF (diluted) + 6 H2O = [K(H2O)6]+ + F-, F- + H2O ↔ HF + OH-.
KF + HF(conc.) = KHF2,
KF + nHF(liquid) = KF·nHF↓, or K[F(HF)n] (n = 1/4).
2KF + H2SO4(conc.) = K2SO4 + 2HF↑ (boiling).
KF + LiOH(saturated) = KОН + LiF↓.
2KF (conc.) + H2SiF6 = K2SiF6 ↓ + 2HF.
KF + SO2 (liquid) = KSO2F.
KF(liquid) → Electrolysis 2K↓(on cathode) + F2↑(on anode).
POTASSIUM HYDROGEN SULFATE KHSO4
Properties potassium hydrogen sulfate KHSO4:
White. It melts without decomposition, on further heating decomposes. Readily soluble in water, creates an acidic environment due to the complete protolysis of the ion HSO4-. Does not form сrystalline hydrates. Neutralized by the alkali. Reacts with hydrogen peroxide.
Obtaining potassium hydrogen sulfate KHSO4:
2KОН + H2SO4 (diluted) = K2SO4 + 2H2O,
KОН + H2SO4 (conc., cold) = KHSO4 + H2O.
K2SO4 (solid) + H2SO4(conc.) = 2KHSO4.
Chemical reactions with potassium hydrogen sulfate KHSO4:
2KHSO4 = K2SO4 + H2SO4 (240°C).
2KHSO4 = K2S2O7 + H2O (320-340°C).
KHSO4 (conc.) + 6H2O = [K(H2O)6]+ + HSO4-,
HSO4- + H2O = SO42- + H3O+ (dilution with water).
KHSO4 + KOH (conc.) = K2SO4 + H2O.
KHSO4 + KCl = K2SO4 + HCl (450-700°C).
KHSO4 + H2O2 (conc.) = KHSO3(O2) + H2O (0°C).
2KHSO4 + TiO2 = Ti(SO4)O + K2SO4 + H2O (300°C).
6KHSO4 + M2O3 = M2(SO4)3 + 3 K2SO4 + 3H2O (300-500°C; M = Al, Cr).
2KHSO4 (saturated) → Electrolysis H2↑ (cathode) + K2S2O6(O2)(anode) (0-7°C).
POTASSIUM SULFATE K2SO4
Properties potassium sulfate K2SO4:
White, heat-resistant. Readily soluble in water (no hydrolysis). Does not form сrystalline hydrates. Participates in exchange reactions. Reduced by hydrogen, carbon.
Obtaining potassium sulfate K2SO4:
2 KO2 + S = K2SO4 (130-140°C),
2 KO2 + SO2 = K2SO4 + O2 (100°C).
2 KОН + H2SO4 (diluted) = K2SO4+ 2H2O,
KОН + H2SO4 (conc., cold) = KHSO4 + H2O.
2 KHSO4 = K2SO4 + H2SO4 (240°C),
2 KHSO4 = K2S2O7 + H2O (320-340°C).
KHSO4 + KОН (conc.) = K2SO4 + H2O.
KHSO4 + KCl = K2SO4 + HCl (450-700°C).
2 KCl (solid) + H2SO4 (conc.) = K2SO4 + 2 HCl↑ (boiling).
K2S (solid) + 2O2 = K2SO4 (t>500°C).
K2S2O7 = K2SO4 + SO3 (t>440°C; impurity SO2, O2).
Chemical reactions with potassium sulfate K2SO4:
K2SO4 (diluted) + 12H2O = 2[K(H2O)6]+ + SO42- (pH 7).
K2SO4 (solid) + H2SO4 (conc.) = 2KHSO4.
K2SO4 + SO3 = K2S2O7.
K2SO4 + BaE2 = BaSO4↓ + 2KE (E = Сl-, OH-).
K2SO4 + BaS2O6 = K2S2O6 + BaSO4↓.
K2SO4 + 4 H2 = K2S + 4H2O (600°C, catalyst Fe2O3).
K2SO4 + 4C (coke) = K2S + 4CO (900°C).
K2SO4 + Ca(OH)2 + 2CO = K(HCOO) + CaSO4 (200°C, pressure),
2 K(HCOO) + O2 = K2CO3 + CO2 + H2O (700°C).
POTASSIUM NITRATE KNO3
Properties potassium nitrate KNO3:
Potash (Indian) nitrate. White. Melts without decomposition, on further heating decomposes. Stable in air. Readily soluble in water with high endo-effect (without hydrolysis). Does not form сrystalline hydrates. Strong oxidizing agent at sintering. In solution recovered only by atomic hydrogen.
| Molar mass | g/mol | 101.10 |
| Density | g/cm3 | 2.109 |
| Melting point | °C | 334.5 |
Obtaining potassium nitrate KNO3:
2KO2 + 2NO2 = 2KNO3 + O2 (70°C).
KOH + HСl (diluted) = KСl + H2O,
KOH + HNO3 (diluted) = KNO3 + H2O.
2KOH (cold) + NO + NO2 = 2KNO2 + H2O,
4KOH(hot) + 4NO2 + O2 = 4 KNO3 + 2H2O.
2KNO2 (diluted, hot) + O2 → time → 2KNO3.
KNO2 + H2O2 = KNO3 + H2O (in the diluted H2SO4),
KNO2 + H2O +Br2 = KNO3 + 2HBr.
Chemical reactions with potassium nitrate KNO3:
2KNO3 = 2 KNO2 + O2 (400-520°C).
KNO3 (diluted) + 6H2O = [K(H2O)6]+ + NO3- (pH = 7).
KNO3 (saturated) + (1-2)HNO3 (conc.) = KNO3·(1-2)HNO3↓ (normal temp.).
KNO3 + 2H0(Zn, diluted HCl) = KNO2 + H2O,
KNO3 + 8H0(Al, conc. KOH) = NH3↑ + 2H2O + KOH (normal temp.).
2KNO3 + (NH4)2SO4 = K2SO4 + 2N2O + 4H2O (230-300°C).
KNO3 + H2SO4(conc.) = HNO3↑ + KHSO4 (vacuum).
2KNO3 + 3C(graphite) + S = N2 + 3CO2 + K2S (combustion of gunpowder).
6KNO3 + 10 Al = 6 KAlO2 + 2Al2O3 + 3 N2 (400°C).
KNO3 + Pb = KNO2 + PbO (350-400°C),
KNO3 (conc.) + Pb (sponge) + H2O = KNO2 + Pb(OH)2 ↓.
3KNO3 + 2KOH + Fe = K2FeO4 + 3KNO2 + H2O (400-420°C).
POTASSIUM BICARBONATE KHCO3
Properties potassium bicarbonate KHCO3:
White, with moderate heating decomposes without melting. Stable in air. Have the structure (K)2(HCO3)2(2 -). Readily soluble in water (hydrolysis on the weak anion). Does not form Crystalline hydrates. Decomposes by acid, neutralized by alkalis. Participates in exchange reactions.
| Molar mass | g/mol | 100.11 |
| Density | g/cm3 | 2.17 |
Obtaining potassium bicarbonate KHCO3:
2 KOH (conc.) + EO2 = K2EO3 + H2O (E = C, S),
KOH + CO2 = KHCO3↓ (in ethanol).
K2CO3 + H2O + CO2 = 2 KHCO3 (30-40° C).
Сhemical reactions with potassium bicarbonate KHCO3:
2 KHCO3 = K2CO3 + CO2 + H2O (100-400° C).
KHCO3 (diluted) + 6H2O = [K(H2O)6]+ + HCO3-,
HCO3- + H2O ↔ H2CO3 + OH-; pKO = 7,63.
KHCO3 + HCl (diluted) = KCl + CO2↑ + H2O.
KHCO3 + KOH (conc.) = K2CO3 + H2O.
6 KHCO3 (conc.) + 3Cl2 = KClO3 + 5KCl↓ + 6 CO2↑ + 3 H2O.
KHCO3 + SO2 = KHSO3 + CO2↑.
4 KHCO3 + 2 CuSO4 = Cu2CO3(OH)2↓ + 2 K2SO4 + 3 CO2↑ + H2O (boiling).
POTASSIUM CARBONATE K2CO3
Properties potassium carbonate K2CO3:
Potash. White. Melts without decomposition, on further heating decomposes. Very soluble in water (strong hydrolysis on the anion), creates a high alkaline environment. Reacts with acids, non-metals, oxides of nonmetals. Participates in exchange reactions.
| Molar mass | g/mol | 138.20 |
| Density | g/cm3 | 2.428 |
| Melting point | °C | 891 |
Obtaining potassium carbonate K2CO3:
4 KO2 + 3 C (graphite) = 2 K2CO3 + CO2 (30° C).
4 KO2 + 2 CO2(humidity) = 2 K2CO3 + 3O2 (normal temp.).
2 KO2 + CO = K2CO3 + O2 (50° C).
2 KOH (conc.) + EO2 = K2EO3 + H2O (E = C, S),
KOH + CO2 = KHCO3↓ (in ethanol).
2 KHCO3 = K2CO3 + CO2 + H2O (100-400° C).
KHCO3 + KOH conc.) = K2CO3 + H2O.
K2SO4 + Ca(OH)2 + 2 CO = 2KHCOO + CaSO4 (200° C, pressure),
2KHCOO + O2 = K2CO3 + CO2 + H2O (700° C).
Chemical reactions with potassium carbonate K2CO3:
K2CO3 = K2O + CO2 (t>1200° C).
K2CO3 - 1.5 H2O = K2CO3 + 1.5 H2O (100-150° C, vacuum).
K2CO3 (diluted) + 12H2O = 2 [K(H2O)6](+) + CO3(2-),
CO32- + H2O ↔ HCO3(-) + OH(-).
K2CO3 + 2 HCl (diluted.) = 2KCl + CO2↑ + H2O.
K2CO3 (saturated) + 2 HClO4 (conc., cold) = 2 KClO4↓ + H2O + CO2↑.
3 K2CO3 (conc.) + 2 H3PO4 (diluted) = 2 K3PO4 + 3 H2O + 3 CO2 ↑.
K2CO3 + 2 HF (diluted) = 2 KF + H2O + CO2↑,
K2CO3 + 4 HF(conc.) = 2 KHF2 + H2O + CO2↑.
K2CO3 + H2O + CO2 = 2 KHCO3 (30-40° C).
K2CO3 (diluted)+ H2O + 2 SO2 = 2 KHSO3 + CO2↑.
K2CO3 + Ca(OH)2 (saturated) = CaCO3 ↓ + 2 KOH.
3 K2CO3 (conc., hot) + 3E2 = 5KE + KEO3 + 3 CO2↑ (E = Cl, Br, I).
3 K2CO3 + 3 H2O (hot) + 2AlCl3 = 2 Al(OH)3↓ + 3 CO2↑ + 6 KCl.
3 K2CO3 + H2O + 2 FeBr3 = 6 KBr + 2 FeO(OH)4 + 3 CO2↑ (boiling).
K2CO3 + BaS2O6 = K2S2O6 + BaCO3↓.
K2CO3 + C (coke) + CaCN2 = 2 KCN + CACO3 (900° C).
K2CO3 + C (NH2)2O = 2 KOCN + 2 H2O (40 °C).
POTASSIUM HYDROXIDE KOH
Properties potassium hydroxide KOH:
Caustic potash. White, very hygroscopic, melts and boils without decomposition. Readily soluble in water with a strong exothermic effect, creates a high alkaline environment. Exhibits the properties basic hydroxides (refers to alkali), neutralized by acids, reacts with oxides of nonmetals, amphoteric oxides and hydroxides. Vigorously absorbs moisture from the air and CO2. Reacts with non-metals, metals.
| Molar mass | g/mol | 56.11 |
| Density | g/cm3 | 2.044 |
| Melting point | °C | 404 |
| Boiling point | °C | 1324 |
Obtaining potassium hydroxide KOH:
2 K + 2 H2O = 2 KOH + H2↑.
4 K + O2 + 2 H2O = 4 KOH.
K2CO3 + Ca(OH)2 (saturated) = CaCO3↓ + 2 KOH.
2 KCl + 2 H2O → Electrolysis H2↑ (cathode) + Cl2(anode) + 2KOH,
2 KCl(melt) (on Hg-cathode)→Electrolysis→ 2K(cathode) + Cl2(anode).
Chemical reactions with potassium hydroxide KOH:
KOH·2H2O = KOH-H2O + H2O (33-40° C, vacuum),
KOH·H2O = KOH + H2O (500° C, vacuum).
KOH (diluted) + 6 H2O = [K(H2O)6](+) + OH(-).
KOH + HCl (diluted) = KCl + H2O,
KOH + HNO3 (diluted) = KNO3 + H2O.
2 KOH + H2SO4 (diluted) = K2SO4 + 2H2O,
KOH + H2SO4 (conc., cold) = KHSO4 + H2O.
KOH (diluted) + H3PO4 (conc.) = KH2PO4 + H2O,
2 KOH (diluted) + H3PO4 (diluted) = K2HPO4 + 2H2O.
3 KOH (conc.) + H3PO4 (diluted) = K3PO4 + 3H2O.
KOH (diluted) + HF (diluted) = KF + H2O,
KOH (conc.) + 2 HF (conc.) = KHF2 + H2O.
KOH (conc.) + HCN = KCN + H2O.
2 KOH (conc., cold) + E2 = KEO + KE + H2O (E = Cl, Br, I),
6 KOH (conc., hot) + 3E2 = KEO3 + 5KE + 3H2O.
12 KOH (conc., hot) + 5 Cl2 + Br2 = 2 KBrO3 + 10 KCl + 6 H2O.
4 KOH + 4O3 = 4 KO3 + O2 + 2 H2O (to 20° C).
2 KOH + 2K = 2 K2O + H2 (400-450° C).
2 (KOH-2H2O) + 2 Al = 2 KAlO2 + 3 H2 + 2 H2O
2 KOH (conc.) + 6 H2O (hot) + 2 Al = 2 K[Al(OH)4] + 3 H2 ↑.
2 KOH (conc.) + EO2 = K2EO3 + H2O (E = C, S),
KOH + EO2 = KHEO3↓ (in ethanol).
6 KOH (conc.) + 5 SiO2 = K4SiO4 (solution) + K2Si4O9 ↓ + 3 H2O.
4 KOH + 6 NO = 4 KNO2 + N2 + 2 H2O (400° C).
2 KOH (diluted) + 2 NO2 = KNO2 + KNO3 + H2O.
2 KOH (cold) + NO + NO2 = 2 KNO2 + H2O,
4 KOH (hot) + 4 NO2 + O2 = 4 KNO3 + 2 H2O.
2 KOH + Al2O3 = 2 KAlO2 + H2O (900-1100° C).
KOH + Al(OH)3 = KAlO2 + 2 H2O (1000° C).
2 KOH (conc., hot) + 3 H2O + Al2O3 = 2K[Al(OH)4].
KOH (conc.) + Al(OH)3 = K[Al(OH)4].
KOH (conc.) + NH4Cl (conc.) = KCl + NH3 ↑ + H2O (boiling).
2 KOH + FeI2 = 2 KI + Fe(OH)2↓ (in atmosphere N2),
2 KOH (diluted) + 2 AgNO3 = Ag2O↓ + H2O + 2 KNO3.
3 KOH (diluted) + AlCl3 = Al(OH)3↓ + 3 KCl.
4 KOH (conc.) + AlCl3 = K[Al(OH)4] + 3 KCl.
KOH (conc.) + 2 H2S + 4 SO2 = 3 K2SO3S + 5H2O.
KOH + (2-4) H2O2 (conc.) →time→ K2O2·(2-4)H2O2↓ (0° C),
K2O2·(2-4) H2O2 →time→ K2O2 + (2-4) H2O2 (over conc. H2SO4).
4KOH (melt)→Electrolysis→ 4K (cathode) + O2↑(anode) + 2H2O.
POTASSIUM OZONIDE KO3
Properties potassium ozonide KO3:
The orange-red. Resistant at cold, decomposes on gentle heating. Has an ionic structure (K +) (-O3). Readily soluble in liquid ammonia, partially reacts with it. Reacts vigorously with water, acids, sulfur. KO3 a strong oxidizing agent.
| Molar mass | g/mol | 87.10 |
| Density | g/cm3 | 1.99 |
Obtaining potassium ozonide KO3:
КO2 + O3 = КO3 + O2 (until 0°C, in the liquid CCl2F2).
4 KOH + 4O3 = 4 КO3 + O2 + H2O (up to 20°C.
Chemical reactions with potassium ozonide KO3:
2 KO3 = 2 KO2 + O2 (20-60°C).
4 KO3 + 2 H2O = 4 KOH + 5 O2↑ (the admixture of radicals OH).
4 KO3 + 4 НСl (diluted, cold) = 4 KСl + 5O2↑ + 2 H2O,
2 KO3 + 4 НСl (diluted, hot) = 2 KСl + Cl2↑ + 2 O2↑ + 2H2O.
4 KO3 + H2O (moisture) + 3 CO2 = K2CO3 + 2KHСO3 + 5O2 (normal temp.).
6 KO3 + 5 S = K2SO4 + 2K2S2O7 (50°C).
KO3 + NH3 (liquid) ↔ NH4O3 + KNH2 (-50°C).
POTASSIUM SUPEROXIDE KO2
Properties potassium superoxide KO2:
The orange-yellow, decomposes when heated, melts under excess pressure. It has the ionic structure (K +) (O2-). Reacts with water, acids, mono-and carbon dioxide, ozone, potassium, ammonia. It is a strong oxidizing agent.
Obtaining potassium superoxide KO2:
K + O2(air) = KO2 (combustion, impurity K2O2).
Chemical reactions with potassium superoxide KO2:
KO2 -O2→(290°C, vacuum) K2O2 -O2 → (530°C) K2O.
2KO2 + H2O = КОН + KHO2 (solution) + O2↑ (0°C),
2KHO2 (solution) → time → 2KОН + O2↑ (normal temp.).
4KO2 + 2H2O (burning) = 4KОН + 3O2↑.
2KO2 + 2HСl (diluted, cold) = 2KСl + H2O2 + O2↑.
2KO2 + H2SO4 (anhydrous) = K2SO4 + O3↑ + H2O (normal temp.).
KO2 + O3 = KO3 + O2 (until 0°C, in the liquid CCl2F2).
2KO2 + S = K2SO4 (130—140°C),
2KO2 + SO2 = K2SO4 + O2 (100°C).
4KO2 + 3C (graphite) = 2K2CO3 + CO2 (30°C).
4KO2 + 2CO2 (humidity) = 2 K2CO3 + 3O2 (normal temp.).
2KO2 + СO = K2CO3 + O2 (50°C).
2KO2 + 2 NO2 = 2KNO3 + O2 (70°C).
KO2 + 3K = 2 K2O (700°C, pressure).
2KO2 + 2NH3 → time → 2KOH + N2 + 2H2O (normal temp.).
POTASSIUM PEROXIDE K2O2
Properties potassium peroxide K2O2:
White (with a impurity of KO2 - light yellow). When heated in air turns yellow and decomposes, melts at a pressure of O2. It has an ionic structure (K+)2(O22-). Sensitive to CO2 of air. Completely decomposed by water, acids, react with metals and nonmetals. Exhibits redox properties.
Obtaining potassium peroxide K2O2:
K + O2 (air) = KO2 (combustion, impurity K2O2),+K →(O2) K2O2 ↓ → (O2, time) KO2 ↓ (- 50° C, in the liquid NH3).
KO2 (-O2)→(290° C, vacuum) K2O2 (-O2)→ (530° C) K2O.
KOH + (2 - 4) H2O2 (conc.) →(time) K2O2·(2 - 4) H2O2 ↓ (0° C),
K2O2-(2 - 4) H2O2 →(time) K2O2 + (2 - 4) H2O2 (over conc. H2SO4).
Chemical reactions with potassium peroxide K2O2:
2 K2O2 = 2 K2O + O2 (t> 500° C).
K2O2 + 2 H2O (cold) = 2 KOH + H2O2,
2 K2O2 + 2 H2O (hot) = 4 KOH + O2.
K2O2 + 2 HCl (diluted, cold) = 2 KCl + H2O2.
2 K2O2 + 2 H2SO4 (diluted, hot) = 2 K2SO4 + 2 H2O + O2↑.
K2O2 + O2 (air) = 2 KO2 (normal temp.).
2 K2O2 + 2 CO2 = 2 K2CO3 + O2,
K2O2 + CO = K2CO3 (normal temp.).
2 K2O2 + C (graphite) = K2CO3 + K2O (100° C).
5 K2O2 + 8 H2SO4 (diluted) + 2KMnO4= 5 O2 ↑ + 2 MnSO4 + 6 K2SO4 + 8 H2O.
POTASSIUM HYDRIDE KH
Properties potassium hydride KH:
White. Decomposes when heated, pressurized H2 melts without decomposition. A strong reducing agent, reacts with water, acids, ammonia, oxygen, chlorine.
Obtaining potassium hydride KH:
2 K + H2 = 2 KH (200—350° C).
Chemical reactions with potassium hydride KH:
2 KH = 2 K + H2 (400° C, vacuum).
KH + H2O = KOH + H2 ↑.
KH + HCl (diluted) = KCl + H2 ↑.
2 KH + O2 = 2 KOH (t> 200° C).
KH + Cl2 = KCl + HCl (400-450° C).
KH + CO2 = KHCOO [t<150° C, pressure].
4 KH + 3 SiO2 = 2 K2SiO2 + Si + 2 H2 (500° C).
KH + NH3 (gas) = KNH2 + H2 (300° C).
POTASSIUM OXIDE K2O
Properties potassium oxide K2O:
White, heat-resistant. Shows the basic properties, reacts vigorously with water (formed highly alkaline solution), acids, acidic and amphoteric oxides, liquid ammonia.
Obtaining potassium oxide K2O:
2K + 2KOH = 2K2O + H2 (450°C).
KO2 (-O2) → (290° C, vacuum) K2O2 (-O2)→ (530°C) K2O.
KO2 + 3 K = 2K2O (700°C, pressure).
2KOH + 2 K = 2K2O + H2 (400-450°C).
K2CO3 = K2O + CO2 (t>1200°C).
Chemical reactions with potassium oxide K2O:
2K2O = K2O2 + 2K (350-430°C).
K2O + H2O = 2KOH.
K2O + 2HCl (diluted) = 2KCl + H2O.
K2O + CO2 = K2CO3 (400°C).
K2O + 2NO2 = KNO2 + KNO3 (150-200°C).
K2O + Al2O3 = 2KAlO2 (1000°C).
K2O + NH3 (liquid) → time → KNH2↓ + KOH (-50°C).
