Sodium hexacyanoferrate(II)

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Crystal compoundsSaltsCyanidesSodium hexacyanoferrate(II)



  Sodium hexacyanoferrate(II)   
Names: sodium hexacyanoferrate(II)
sodium hexacyanoferroate
sodium cyanoferrate
sodium ferrocyanide
yellow prussiate of soda
gelbnatron

Formula: Na4[Fe(CN)6]
Na4[Fe(CN)6] · 10H2O
SMILES: [C-]#N.[C-]#N.[C-]#N.[C-]#N.[C-]#N.[C-]#N.[Na+].[Na+].[Na+].[Na+].[Fe+2]
Molar mass: 303.913 g/mol (anhydrous)
484.062 g/mol (decahydrate)
Density: 1.458 g/cm3 (anhydrous)
1.329 g/cm3 (decahydrate)
Crystal system: monoclinic (decahydrate)
α=90°
90°  
, γ=90°
90°  

Forms:
https://media.crystalls.info/w/uploads/media/Rhombic_dodecahedron.json


Color: bright-yellow
Melting point: 650°C
923.15 K
1,202 °F
1,661.67 °R
(anhydrous)
Decomposition point: 81.5°C
354.65 K
178.7 °F
638.37 °R
(decahydrate)
435°C
708.15 K
815 °F
1,274.67 °R
(anhydrous)
Refractive index: 1.531 (decahydrate)
Electrical properties: dielectric
Magnetic properties: diamagnetic
Stability: slightly erodes (decahydrate)
Hardness: relatively strong
Toxicity: slightly toxic

==Description == Inorganic complex compound, salt of alkaline metal sodium and inorganic ferrocyanide acid. From water solutions crystallizes as decahydrate.

Synthesis

Reaction between potassium ferrocyanide, hydrochloric acid and sodium hydroxide

Chemical equation:

K4[Fe(CN)6] + 4HCl = H4[Fe(CN)6]↓ + 4KCl
H4[Fe(CN)6] + 4NaOH = Na4[Fe(CN)6] + 4H2O

For preparation 100g of sodium hexacyanoferrate(II) decahydrate a 87.26g of potassium ferrocyanide trihydrate, 33.05g of sodium hydroxide and 81.43g of 37% hydrochloric acid is required.

Add to the flask with potassium ferrocyanide solution small parts of hydrochloric acid solution and stir. The large amount of poorly soluble precipitate will form. Settle it out and wash it from soluble impurities few times. Add to flask with hot concentrated solution of sodium hydroxide small amount of that precipitate with intense stirring. Heat it to 100°C for few minutes for reaction completion and then filter out. For purifying compound from hydroxide add large amount of cold ethanol, acetone or toluene to solution, salt will settle to the bottom in the form of fine crystals or powder. Filter precipitate and wash it with small amount of the same solvent, then filter the solution and use it for crystal growing.

====Reaction between prussian blue and sodium hydroxide==== Chemical equation:

Fe4[Fe(CN)6]3 + 12NaOH = 3Na4[Fe(CN)6] + 4Fe(OH)3

For preparation 100g of sodium hexacyanoferrate(II) decahydrate a 33.05g of sodium hydroxide and 59.17g of prussian blue is required.
Add to flask with prussian blue small amount of water until it will become a thick slurry. Then add small parts of diluted hydroxide solution with intense stirring. Mixture will change color from dark-blue to dark-brown, become more homogeneous and could even boils because of exothermic. Heat it to 100°C for few minutes for reaction completion, filter out a precipitation of iron hydroxide.

====Reaction between potassium ferrocyanide and sodium cation-exchange resin==== Chemical equation:

K4[Fe(CN)6] + 4Na+ = Na4[Fe(CN)6] + 4K+

For preparation 100g of sodium hexacyanoferrate(II) decahydrate a 73.95g of potassium ferrocyanide trihydrate is required.
Add warm potassium ferrocyanide solution to chemical column with sodium cation exchange resin and shake it.

==Influence of temperature== Growing at higher temperature gives mostly polycrystalline.

Storage conditions

Store in its original form or under several layers of varnish at average humidity and room temperature. Do not store in matchboxes or cotton wool and do not heat.

Notes

Slowly reacts with diluted sulfuric acid with poisonous hydrocyanic acid emission, so be careful. Concentrated acid decomposes it to carbon monoxide, another ones gives participate of ferrocyanide acid.

Solubility

Temperatureg/100g of water
(anhydrous)(decahydrate)
0°C
273.15 K
32 °F
491.67 °R
~11.4
11.4 g/100g
10.233 %
~17.3
17.3 g/100g
14.749 %
10°C
283.15 K
50 °F
509.67 °R
~14.7
14.7 g/100g
12.816 %
~24.6
24.6 g/100g
19.743 %
15°C
288.15 K
59 °F
518.67 °R
~16.3
16.3 g/100g
14.015 %
~28.2
28.2 g/100g
21.997 %
20°C
293.15 K
68 °F
527.67 °R
17.9
17.9 g/100g
15.182 %
31.85
31.85 g/100g
24.156 %
25°C
298.15 K
77 °F
536.67 °R
20.725
20.725 g/100g
17.167 %
~38.8
38.8 g/100g
27.954 %
30°C
303.15 K
86 °F
545.67 °R
23.5
23.5 g/100g
19.028 %
~43.5
43.5 g/100g
30.314 %
40°C
313.15 K
104 °F
563.67 °R
30.2
30.2 g/100g
23.195 %
~58.6
58.6 g/100g
36.948 %
50°C
323.15 K
122 °F
581.67 °R
~36.4
36.4 g/100g
26.686 %
~74.6
74.6 g/100g
42.726 %
60°C
333.15 K
140 °F
599.67 °R
42.5
42.5 g/100g
29.825 %
~90.5
90.5 g/100g
47.507 %
70°C
343.15 K
158 °F
617.67 °R
~50.9
50.9 g/100g
33.731 %
~118
118 g/100g
54.128 %
80°C
353.15 K
176 °F
635.67 °R
59.2
59.2 g/100g
37.186 %
~145.3
145.3 g/100g
59.234 %
90°C
363.15 K
194 °F
653.67 °R
~61.1
61.1 g/100g
37.927 %
~151
151 g/100g
60.159 %
100°C
373.15 K
212 °F
671.67 °R
63.0
63 g/100g
38.65 %
156.5
156.5 g/100g
61.014 %
Insoluble in ethanol, methanol, acetone, diethyl ether, toluene, aniline, pyridine, ethyl acetate and isopropanol.

==Gallery==


==Sources==


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