More about Group
+3 chlorides

The information below shows that the product of reaction of Group 15 (+3) chlorides with water varies with the nature of the element.

  • It is obvious from this information that the reaction of NCl3 with water reacts quite differently to the other Group 
     halides.
    This is because the polarity of the N–Cl bond is δ– N–Cl δ+.  Thus the oxidation state of nitrogen in NCl3 is -3 (the same as in NH3). The oxidation state of Cl is +1 as in HOCl.  The result of this is that reaction with water results in an N-H bond (contrasted with an E-O bond for the other elements) and an O-Cl bond (in contrast to the HCl bond formed for the other elements).
     
  • The phosphorus chloride reacts to give an oxoacid (as seen earlier).
  • The less metallic elements give oxides (recall that both of these are amphoteric).
  • The one metallic element (Bi) gives an oxochloride (BiO+ is equivalent to (Bi-OH2)3+ - 2H+)

chloride NCl3 PCl3 AsCl3 SbCl3 BiCl3
reacts with H2O to give NH3 and HOCl H3PO3 + HCl As2O3 + HCl Sb2O3 + HCl BiOCl + HCl
 
Dr Sheila Woodgate
© The University of Auckland 2002