--%>
Assignment Help - homework help

Describe characteristics of halides and oxides.

Halides characteristics

(i) These trihalides are mainly covalent with the exception of BiF3 which is ionic.

(ii) The ionic character of trihalides increases in going down the group.

(iii) Like hydrides, these trihalides have pyramidal structure.

(iv) These trihalides except NX3 can be easily hydrolysed by water.

The inability of trihalides of N to hydrolyse is attributed to the non-availability of vacant d-orbitals in nitrogen.

(v) The trihalides of P, As, Sb (especially fluorides and chlorides) act as Lewis acids and combine with Lewis bases

PF3 + F2  1973_halides and oxides.png  PF5

SbF3 + 2F-  1973_halides and oxides.png   [SbF5]2-

(vi) The pentahalides in general, have less thermal stability as compared to trihalides.

(vii) All the pentahalides act as Lewis acids. It is because the central atom can easily accept the halide ions due to presence of vacant d-orbital and can extend their co-ordination number.

(viii) PCl5 exists as molecule in gaseous state but in solid state it exists as [PCl4]+[PCl6]- and is ionic in nature. PBr5, PI5 also exists in the ionic form in solid state.

Reactivity towards oxygen: the elements of this group combine with oxygen directly or indirectly to form a large number of different types of oxides.

Nature of oxides

All the oxides of nitrogen except NO and N2O and phosphorus are strongly acidic: oxides of arsenic are weakly acidic; oxides of antimony are amphoteric and those of bismuth are weakly basic.

Reason: the change in character from acidic to basic can be explained on the basis of the size of atoms. As the size of nitrogen atom is small and it has a strong positive field, it interacts with water more strongly pulling the electron pair between O - H bond and thus release of H+ ions.

However, this tendency diminishes with the increase in size and therefore decreases the acidic character or conversely increases the basic character.

As far as the stability of the oxides is connected it is found that oxides having elements in the higher oxidation state become less stable as we move down to group. This is because of the import pair effect.

   Related Questions in Chemistry

  • Q : Problem on volumetric flow rate Methane

    Methane containing 4 mol% N2 is flowing through a pipeline at 105.1 kpa and 22 °C. To check this flow rate, N2 at the same temperature and pressure are introduced to the pipeline at the rate of 2.83 m3/min. At the end of the pipe (

    		•
  • Q : Question on Mole fraction Mole fraction

    Mole fraction of any solution is equavalent to: (a) No. of moles of solute/ volume of solution in litter (b) no. of gram equivalent of solute/volume of solution in litters (c) no. of  moles of solute/ Mass of solvent in kg (d) no. of moles of any

    		•
  • Q : Functions of centrioles Describe

    Describe briefly the functions of centrioles?

    		•
  • Q : Molarity of solution Help me to go

    Help me to go through this problem. When 7.1gm Na2SO4 (molecular mass 142) dissolves in 100ml H2O , the molarity of the solution is: (a) 2.0 M (b) 1.0 M (c) 0.5 M (d) 0.05 M

    		•
  • Q : How to establish nomenclature for

    In the common chemistry terminologies, aliphatic halogen derivatives are named as alkyl halides. The words, n-, sec-, tert-, iso-, neo-, and amyl are

    		•
  • Q : Adiabatic compression A lean natural

    A lean natural gas is available at 18oC and 65 bars and must be compressed for economical pipeline transportation. The gas is first adiabatically compressed to 200 bars and then isobarically (i.e. at constant pressure) cooled to 25°C. The gas, which is

    		•
  • Q : Explosions produce carbon dioxide

    Illustrate all the explosions produce carbon dioxide?

    		•
  • Q : Solutions The relative lowering of

    The relative lowering of vapour pressure of 0.2 molal solution in which solvent is benzene

    		•
  • Q : Isotonic Solutions Which one of the

    Which one of the following pairs of solutions can we expect to be isotonic at the same temperature:(i) 0.1M Urea and 0.1M Nacl  (ii) 0.1M Urea and 0.2M Mgcl2  (iii) 0.1M Nacl and 0.1M Na2SO4  (iv) 0.1M Ca(NO3<

    		•
  • Q : What is laser and explain its working?

    Laser action relies on a non-Boltzmann population inversion formed by the absorption of radiation and vibrational deactivation that forms a long lived excited electronic state. An excited state molecule can move to a lower energy state or return to the

    		•