--%>
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 : Problem on solutions The 2N aqueous

    The 2N aqueous solution of H2S04 contains: (a) 49 gm of H2S04 per litre of solution (b) 4.9 gm of H2S04 per litre of solution (c) 98 gm of H2S04

    		•
  • Q : What is chemisorption or chemical

    When the forces of attraction existing between adsorbate particles and adsorbent almost of the same strength as chemical bonds, the adsorption is called chemical adsorption. This type of adsorption is also known as chemisorptions. Since forces of attraction existing b

    		•
  • Q : Haloalkanes define primary secondary

    define primary secondary and tertiary alkyl halides with examples

    		•
  • Q : Some basic concepts of chemistry an

    an atom of an element is 10.1 times heavier than the mass of a carbon atom.What is its mass in amu?

    		•
  • Q : Rotational energy and entropy due to

    The entropy due to the rotational motion of the molecules of a gas can be calculated. Linear molecules: as was pointed out, any rotating molecule has a set of allowed rotational energies. For a linear molecule the

    		•
  • Q : Problem based on molecular weight

    Select the right answer of the question. Molecular weight of urea is 60. A solution of urea containing 6g urea in one litre is : (a)1 molar (b)1.5 molar (c) 0.1 molar (d) 0.01 molar

    		•
  • Q : Problem based on molality of glucose

    Select the right answer of the question. If 18 gm of glucose (C6H12O6) is present in 1000 gm of an aqueous solution of glucose, it is said to be: (a)1 molal (b)1.1 molal (c)0.5 molal (d)0.1 molal

    		•
  • Q : Finding strength of HCL solution Can

    Can someone please help me in getting through this problem. 1.0 gm of pure calcium carbonate was found to require 50 ml of dilute  HCL for complete reaction. The strength of the HCL  solution is given by: (a) 4 N  (b) 2 N  (c) 0.4 N  (d) 0.2 N

    		•
  • Q : Mole fraction of water Give me answer

    Give me answer of this question. A solution contains 25%H2O 25%C2H5OH , and 50% CH3 COOH by mass. The mole fraction of H2O would be: (a) 0.25 (b) 2.5 (c) 0.503 (d) 5.03.

    		•
  • Q : Calculating molarity of a solution

    Select the right answer of the question .The molarity of a 0.2 N N2Co3 solution will be: (a) 0.05 M (b) 0.2 M (c) 0.1 M (d)0.4 M

    		•