Home | | Chemistry 12th Std | Phosphorous trichloride

Phosphorous trichloride - Preparation, Properties, Structure, Uses | Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail |

Chapter: 12th Chemistry : p-Block Elements-II

Phosphorous trichloride

When phosphorous trichloride is hydrolysed with cold water it gives phosphorous acid.

Phosphorous trichloride:


Preparation:

When a slow stream of chlorine is passed over white phosphorous, phosphorous trichloride is formed. It can also be obtained by treating white phosphorous with thionyl chloride.

P4 + 8SOCl→ 4PCl3 + 4SO2 + 2S2Cl2


Properties

When phosphorous trichloride is hydrolysed with cold water it gives phosphorous acid.

PCl3 + 3H2O → H3PO3 + 3HCl

This reaction involves the coordination of a water molecule using a vacant 3d orbital on the phosphorous atom following by elimination of HCl which is similar to hydrolysis of SiCl4.

PCl3 + H2O → PCl3.H2O → P(OH)Cl2 + HCl

This reaction is followed by two more steps to give P(OH)3 or H3PO3.

HPOC12 + H2O → H2PO2Cl + HCl

H2PO2Cl + H2O → H2PHO3 + HCl

Similar reactions occurs with other molecules that contains alcohols and carboxylic acids.

C2H5OH + PCl→ C2H5Cl + H3PO3

C2H5COOH + PCl→ C2H5COCl + H3PO3



Uses of phosphorus trichloride:

Phosphorus trichloride is used as a chlorinating agent and for the preparation of H3PO3.

Tags : Preparation, Properties, Structure, Uses Preparation, Properties, Structure, Uses
Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail


Copyright © 2018-2021 BrainKart.com; All Rights Reserved. (BS) Developed by Therithal info, Chennai.