Sodium perchlorate

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Sodium perchlorate
Sodium perchlorate by Zyklon-A.jpg
Sodium perchlorate sample
Sodium perchlorate structure.png
Names
IUPAC name
Sodium perchlorate
Other names
Sodium chlorate(VII)
Sodium hyperchlorate
Identifiers
Jmol-3D images Image
Properties
NaClO4
Molar mass 122.44 g/mol
Appearance White crystalline solid
Odor Odorless
Density 2.4994 g/cm3 (anhydrous)
2.02 g/cm3 (monohydrate)
Melting point 468 °C (874 °F; 741 K) (decomposes, anhydrous)
130 °C (266 °F; 403.15 K) (monohydrate)
Boiling point 482 °C (900 °F; 755 K) (monohydrate, decomposes)
209.6 g/100 ml (25 °C, anhydrous)
209 g/100 ml (15 °C, monohydrate)
Solubility Soluble in acetone
Insoluble in benzene, chloroform, toluene
Solubility in acetone 52 g/100 g
Vapor pressure ~0 mmHg
Hazards
Safety data sheet ScienceLab (anhydrous)
ScienceLab (monohydrate)
Flash point Non-flammable
Related compounds
Related compounds
Sodium hypochlorite
Sodium chlorite
Sodium chlorate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Sodium perchlorate is an inorganic salt of sodium, with the chemical formula NaClO4.

Properties

Chemical

Sodium perchlorate is a powerful oxidizer, though it's not as useful in pyrotechnics as the potassium salt due to its hygroscopicity.

It will react with a strong mineral acid, such as sulfuric acid, to form perchloric acid. This can be isolated by vacuum distillation.

NaClO4(aq) + H2SO4(aq) ↔ NaHSO4 (aq) + HClO4(aq)

Physical

Sodium perchlorate is a white crystalline salt. It is hygroscopic, forming a monohydrate. It is highly soluble in water, 209 g/100 ml at 25 °C. It is also soluble in low chain alcohols.

Availability

Sodium perchlorate used to be available globally, but recent regulations have restricted its possession in Europe. Perchlorates can still be purchased from some online vendors, but in limited quantities. Purchases using some form of identification have a good chance of being tracked by a government agency. In the US, perchlorates are still widely available through pyrotechnic companies as well as lab suppliers.

Preparation

Sodium perchlorate is produced by anodic oxidation of sodium chlorate (which in turn is made from the electrolysis of a solution of sodium chloride) at an inert electrode, such as platinum.[1]

ClO3- (aq) + H2O (l) → ClO4- (aq) + H2 (g)

However when using platinum as an anode, its wear rate will increase as the chlorate concentration starts to decrease, and below 50g/l it may be excessive; high temperatures also increase its wear rate. Wear rates from manufacturers have been reported as 3 to 6 grams of Pt per ton of sodium perchlorate.[2]

Sodium perchlorate can also be prepared by thermal decomposition of sodium chlorate, yielding sodium chloride as side product. Since the sodium perchlorate can also decompose and the sodium chlorate can give off oxygen without making perchlorate, this can be a lossy way to produce this compound.

4 NaClO3 → NaCl + 3 NaClO4

The reaction is considerably faster than a perchlorate cell however. The main drawbacks are the difficulty in holding the temperature (since sodium perchlorate also decomposes) and the danger of the molten chlorate. It is doubtful if this method scales well. The resulting reaction mixture can be separated by dissolution of the perchlorate in acetone, since both sodium chlorate and sodium chloride are rather poorly soluble in it.[3][4]

Projects

Handling

Safety

Sodium perchlorate is a powerful oxidizer. It should be kept away from organic substances and strong reducing agents. Unlike chlorates, perchlorate mixtures with sulfur are relatively stable.

It is moderately toxic, as in large amounts it interferes with iodine uptake into the thyroid gland.

Storage

NaClO4 should be stored in tightly sealed bottles as it is slightly hygroscopic. It should be kept away from any strong acidic vapors to prevent the formation of anhydrous perchloric acid, a fire and explosion hazard. It must also be kept away from any flammable materials.

Disposal

Sodium perchlorate should not be poured down the drain or dumped into environment. It must be neutralized with a reducing agent to NaCl first.

Sodium perchlorate can be destroyed with metallic iron under UV light, in the absence of air.[5]

References

  1. http://www.utahpyro.org/compositions/HowToMakeSodiumPerchlorate.pdf
  2. http://www.oocities.org/capecanaveral/campus/5361/chlorate/naperchl.html
  3. Liptakov's video on producing sodium perchlorate from sodium chlorate by thermal decomposition: https://www.youtube.com/watch?v=1Ylt2ZKJlME
  4. https://patents.google.com/patent/US3151935A/en
  5. Perchlorate in the Environment (2000), Edward Todd Urbansky, pag. 106

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