--%>
Assignment Help - homework help

Explain group 15 elements.

The various elements of this group differ from one another in their chemical reactivity. Nitrogen differs from the rest of the members of the group due to its smaller size, high electronegativity, high ionization enthalpy and non-availability of d-orbitals. Nitrogen is chemically comparatively less reactive. It is because of high stability of its molecule, N2 in which the two nitrogen atoms are linked by triple bond (N ≡ N) and thus, possess high bond strength (941.4 kJ mol-1).


Among the elements of this group only nitrogen has a unique ability to form p π-p π multiple bonds with itself as well as with carbon oxygen. The multiple bonding in nitrogen occurs due to its small size. Nitrogen, thus, forms a diatomic molecule, N2. On the other hand, phosphorus, arsenic and antimony form tetrahedral molecules in their elemental state with formula E4. Each P atom is linked to three other atoms with P - P - P bond angle equal to 60°. Though phosphorus and heavier members of the family do not form p π-p πmultiple bonds easily, yet the multiple bonding of the type d π-p π can readily occur in these elements. This type of bonding is prominent for the phosphorus as is reflected in the formation of compounds such as POX3, RN = PX2, R3P = O or R3P = CH2 (R = alkylgroup).

Phosphorus and arsenic can form d π-p π bond also with transition metals their compounds like P(C2H3) and As(C6H5)3 an actas ligands. Recently, a few compounds of phosphorus and arsenic having multiple bonding like P = C, P ≡ C, P = N, P = P and As = Asgroups have been synthesized.

The common chemical characteristics of group 15 elements are discussed below:

Reactivity for hydrogen: the elements of group 15 form hydrides having the general formula EH3. All these are covalent in nature. These hydrides are listed below:

66_Group 15.png 

Reactivity towards halogen

All the elements of group 15 form two series of halides, i.e. trihalides and pentahalides of the type EX3 and EX5.

Nitrogen does not form pentahalides because of non-availability of the d-orbitals in its valence shell. Penta-halides are more covalent than trihalides. All these trihalides of these elements except those of nitrogen are stable. In case of nitrogen simply NF3 is known to be stable. The trihalides except BiF3 are predominantly covalent in character.

   Related Questions in Chemistry

  • Q : Simulate the column in HYSYS The

    The objective of this work is to separate a binary mixture and to cool down the bottom product for storage. (Check table below to see which mixture you are asked to study). 100 kmol of feed containing 10 mol percent of the lighter component enters a continuous distillation column at the m

    		•
  • Q : Theory of three dimensional motion

    Partition function; that the translational energy of 1 mol of molecules is 3/2 RT will come as no surprise. But the calculation of this result further illustrates the use of quantized states and the partition function to obtain macroscopic properties. The partition fu

    		•
  • Q : Significance of the organic chemistry

    Describe some of the significance of the organic chemistry in brief?

    		•
  • Q : Problem on equilibrium composition The

    The catalytic dehydrogenation of 1-butene to 1,3-butadiene, C4H8(g) = C4H6(g)+H2(g) is carried out at 900 K and 1 atm.

    Q : Benzoic acid is weaker than paranitro

    Briefly state that Benzoic acid is weaker than paranitro benzoic acid?

    		•
  • Q : P- block why pentahalids are more

    why pentahalids are more covalent than tetrahalids

    		•
  • Q : Explain preparation and properties of

    It may be prepared by the action of phosphorus on thionyl chloride.P4 + 8SOCl2    4

    		•
  • Q : What is covalent radii? Explain its

    Average covalent radii can be assigned on the basis of molecular structures. The accumulation of structural data by spectroscopic studies and both electron and x-ray diffraction studies allows one to investigate the possibili

    		•
  • Q : What is synthetic rubber and how it

    To meet human needs, scientists have started preparing synthetic rubbers. Besides having similar properties as natural rubbers they are tougher, more flexible and more durable than natural rubber. They are capable of getting stretched to twice its length. Though, it reverts to its original shape

    		•
  • Q : Problem on Osmotic Pressure of solution

    The osmotic pressure of a 5% solution of cane sugar at 150oC  is (mol. wt. of cane sugar = 342)(a) 4 atm (b) 3.4 atm (c) 5.07 atm (d) 2.45 atmAnswer: (c) Π = (5 x 0.0821 x 1000 x 423)/(342 x 100) = 5.07 atm

    		•