--%>
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 : Explain the catalyst definition and

    Catalyst is a substance which accelerates the rate of a chemical reaction without undergoing any change in its chemical composition or mass during the reaction. The phenomenon of increasing the rate of a reaction with the help of a catalyst is known as catalysis.

    		•
  • Q : Analytical chemistry 37% weight of HCl

    37% weight of HCl and density is 1.1g/ml. find molarity of HCl

    		•
  • Q : Examples of reversible reaction

    Describe some examples of a reversible reaction?

    		•
  • Q : Problem based on molarity Select the

    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 : Molal elevation constant of water The

    The boiling point of 0.1 molal aqueous solution of urea is 100.18oC  at 1 atm. The molal elevation constant of water is: (a) 1.8    (b) 0.18   (c) 18    (d) 18.6Answer: (a) Kb

    		•
  • Q : Liquid surfaces The surface between a

    The surface between a liquid and a vapour distinguishes these fluids. The surface tension of liquids can be looked upon as that the property which draws a liquid together and forms a liquid vapour interface, therefore, distinguishing liquids from gases.<

    		•
  • Q : Solutions The normality of 10 lit.

    The normality of 10 lit. volume hydrogen peroxide is: (a) 0.176 (b) 3.52 (c) 1.78 (d) 0.88 (e)17.8

    		•
  • Q : Molecular basis of third law. The

    The molecular, or statistical, basis of the third law can be seen by investigating S = k in W.The molecular deductions of the preceding sections have led to the same conclusions as that stated in the third law of thermodynamics, namely, that a value can be

    		•
  • Q : Acid Solutions Choose the right answer

    Choose the right answer from following. Volume of water needed to mix with 10 ml 10N NHO3 to get 0.1 N HNO3: (a) 1000 ml (b) 990 ml (c) 1010 ml (d) 10 ml

    		•
  • Q : Number of moles present in water

    Provide solution of this question. How many moles of water are present in 180 of water: (a)1 mole (b)18 mole (c)10 mole (d)100 mole

    		•