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Toxicological Profile for Cyanide. Atlanta (GA): Agency for Toxic Substances and Disease Registry (US); 2006 Jul.

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Toxicological Profile for Cyanide.

Atlanta (GA): Agency for Toxic Substances and Disease Registry (US); 2006 Jul.

Table 4-2 Physical and Chemical Properties of Cyanide and Compounds

PropertyHydrogen cyanideSodium cyanidePotassium cyanideCalcium cyanidePotassium silver cyanideCyanogenCyanogen chlorideCopper(l) cyanideAmmonium thiocyanate
Molecular weight27.03 a 49.01 a 65.12 a 92.12 a 199.01 b 52.04 a 61.47 a 89.56 a 76.12 a
ColorColorless b White b ; colorless a White b ; colorless a White a White b Colorless a Colorless d White to cream-colored b Colorless a
Physical stateGas or liquid b Solid b Solid b Solid a Solid b Gas a Gas d Solid a Solid a
Melting point, °C−13.4 b 563.7 a 634.5 a Decomposes at >350 °C a No data−27.9 a −6 a 473 (in N2) a 149.6 a
Boiling point, °C25.70 c 1496 a No dataNo dataNo data−20.7 a 13.8 b ;12.7 a Decomposes a 170 decomposes a
Density, g/cm 3 0.6884 (liquid at 20 °C) c 1.60 (for cubic form) c 1.553 (for cubic form) c 1.8–1.9 (commercial product) c 2.36 a 0.9577 at −21.17 °C a 1.186 b 2.92 a 1.305 a
OdorFaint bitter almond odor d Odorless when dry, emits slight odor of HCN in damp air b Faint bitter almond odor b Faint bitter almond odor b No dataAlmond-like odor b Highly irritating h No dataOdorless b
Odor threshold:
Water0.17 ppm (w/v) e No dataNo dataNo dataNo dataNo dataNo dataNo dataNo data
Air0.58 ppm (v/v) e ; 0.8–4.4 ppm f No dataNo dataNo dataNo data230 ppm; irritating at 15 ppm f 1 ppm f No dataNo data
Solubility:
WaterMiscible a 48 g/100 mL at 10 °C c 71.6 g/100 mL at 25 °C c Soluble in water with gradual liberation of HCN b Soluble b ; 250 g/L (25 °C) m 450 cc/100 cc (20 °C) a Soluble b ; 27.5 mg/L (25 °C) m 2.6 mg/L (25°C) m 128 g/100 cc at 0 °C a ; Very soluble in hot water a ; 181 g/100 cc at 25 °C p
Organic solvent(s)Soluble in ethanol, ether a Slightly soluble in ethanol a and formamide c Slightly soluble in ethanol c and methanol b Slightly soluble in ethanol a Soluble in ethanol and ethyl ether a Soluble in ethanol and ethyl ether b Insoluble in alcohol f Very soluble in ethanol; soluble in acetone and methanol; insoluble in ethyl acetate and chloroform b
Partition coefficients:
Log Kow0.66 g ; 1.07 (calc.) h 0.44 g No dataNo dataNo data0.07 n No dataNo dataNo data
Log KocNo dataNo data3.0 (calculated) l No dataNo dataNo dataNo dataNo dataNo data
Vapor pressure, mm Hg630 (at 20 °C) f 0.76 at 800 °C c No dataNo dataNo data3,800 at 20 °C o 760 at 13.8 °CNo dataNo data
Henry’s law constant5.1×10 −2 atm-m 3 /mol i No dataNo dataNo dataNo dataNo data3.2×10 −3 atm-m 3 /mol m No dataNo data
Autoignition temperature538 c No dataNo dataNo dataNo dataNo dataNo dataNo dataNo data
Flashpoint, °C−17.8 (closed cup) c No dataNo dataNo dataNo dataNo dataNo dataNo dataNo data
Flammability limits5.6–40% j Not combustible j Not combustible j Not combustible j No data6.6–32% in air j Not combustible f Does not readily ignite f May be combustible f
Conversion factors:
mg/m 3 to ppm in air, 20 °C1 mg/m 3 = 0.890 ppmNA k NA k NA k NA k 1 mg/m 3 = 0.462 ppm1 mg/m 3 = 2.5 ppmNA k NA k
ppm to mg/L in waterppm (w/v) = mg/L = μg/mLppm (w/v) = mg/L = μg/mLppm (w/v) = mg/L = μg/mLppm (w/v) = mg/L = μg/mLppm (w/v) = mg/L = μg/mLppm (w/v) = mg/L = μg/mLppm (w/v) = mg/L = μg/mLppm (w/v) = mg/L = μg/mLppm (w/v) = mg/L = μg/mL
ppm to mg/kg in soluble samplesppm (w/w) = mg/kg = μg/gppm (w/w) = mg/kg = μg/gppm (w/w) = mg/kg = μg/g ppm (w/w) = mg/kg = μg/gppm (w/w) = mg/kg = μg/gppm (w/w) = mg/kg = μg/gppm (w/w) = mg/kg = μg/gppm (w/w) = mg/kg = μg/g
Explosive limitsUpper, 40%; lower, 5.6% f No dataNo dataNo dataNo dataNo dataNo dataNo dataNo data