Pyrophosphoryl Chloride

Cas no

13498-14-1

Chemical name

Cl₂P(=O)OP(=O)Cl₂

Formula

Cl₄O₃P₂

Molecular weight

251.76

Properties

colorless, smoking, corrosive liquid

Specific gravity

1.79-1.81

Assay

NLT 99.5 % (Quadra distilled)

Description

It is a colorless liquid with a boiling point of 110°C at 10-mm pressure. The specific density (weight per ml) is between 1.808 to 1.814 at 20°C. It can be stored for about 6 months at low temperature without any decomposition.

Packing

Comes in 2.5 Litre glass bottles (Equivalent to 4 kgs material) which is packed in EPS moulded Themocole packing. Four bottles/ packs are then packed in 9 mm thick wooden boxes which are specially approved by Cargo AIR Craft.

Method of analysis

(a)by Acidity

Take 50 ml N/1 NaOH in a 250-ml beaker and chill it in an ice bath. Transfer about 1gm of sample in a chilled N/1 NaOH standard drop by drop with constant stirring. Control the addition of sample in such a way that there is no violent reaction. Set aside the beaker for 10 minutes and heat the beaker in a water bath for about 30 minutes, cool and titrate it with N/1 H₂SO₄ using Methyl Red/Bromocresol green (7 parts Methyl Red and 80 parts of Bromocresol green) as indicators. The end point being yellow. Retain the solution for Assay (b).1ml N/1 NaOH = 0.04200 gms P₂O₃Cl₄

(b) By Chloride

Dilute the content of the beaker from Assay (a) to 250 ml with water. Add 10 ml of nitric acid 50ml of N/10 Silver Nitrate and 3 ml of Nitrobenzene to 50 ml of the diluted sample. /10 Ammonium Thiocynate using Ferric Ammonium Sulfate as indicator. Shake the sample well after each addition of the titrant 1 ml of N/10 AgNO3 = 0.00629 gms of P₂O₃C1⁴

REACTION

Pyrophosphoryl Chloride reacts with alcohol like (Dexa Methazone or Beta Methazone) and forms a phosphate salt. On addition of Sodium Hydroxide it forms Disodium Phosphate (soluble salt).