--%>
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 : Film Mass Transport Sulfur trioxide

    Sulfur trioxide (SO3) is manufactured by the gas-phase oxidation of SO2 over a platinum catalyst: SO2 + ½ O2 à SO3 The catalyst is a non-porous ext

    		•
  • Q : Explain the process of adsorption in

    The process of adsorption can occurs in solutions also. This implies that the solid surfaces can also adsorb solutes from solutions. Some clarifying examples are listed below: (i) When an aqueous solution of ethano

    		•
  • Q : Define Bond Energies - Bond Charges

    Energy changes in some chemical reactions can be used to deduce the energies of chemical bonds. Our understanding of the molecular basis of thermodynamic properties is extended when we ask why the enthalpy change for a reaction is what it is. We deduce,

    		•
  • Q : Cations Chromium(III) hydroxide is

    Chromium(III) hydroxide is highly insoluble in distilled water but dissolves readily in either acidic or basic solution. Briefly explain why the compound can dissolve in acidic or in basic but not in neutral solution. Write appropriate equations to support your answer

    		•
  • Q : Atmospheric pressure Give me answer of

    Give me answer of this question. The atmospheric pressure is sum of the: (a) Pressure of the biomolecules (b) Vapour pressure of atmospheric constituents (c) Vapour pressure of chemicals and vapour pressure of volatile (d) Pressure created on to atmospheric molecules

    		•
  • Q : Molecular weight of solute Select right

    Select right answer of the question. A dry air is passed through the solution, containing the 10 gm of solute and 90 gm of water and then it pass through pure water. There is the depression in weight of solution wt by 2.5 gm and in weight of pure solvent by 0.05 gm. C

    		•
  • Q : Molal concentration Select the right

    Select the right answer of the question. If one mole of any substance is present in of solvent, then: (a) It shows molar concentration (b) It shows molal concentration (c) It shows normality (d) It shows strength.

    		•
  • Q : What is solvent dielectric effect?

    Ionic dissociation depends on the dielectric constant of the solvent.The Arrhenius that ions are in aqueous solutions in equilibrium with parent molecular species allows many of the properties of ionic solutions to be understood. But difficulties began to

    		•
  • Q : Statement of Henry law Determine the

    Determine the correct regarding Henry’s law: (1) The gas is in contact with the liquid must behave as an ideal gas (2) There must not be any chemical interaction among the gas and liquid (3) The pressure applied must be high (4) All of these.

    		•
  • Q : Ddd 4) The addition of S2- ion to

    4) The addition of S2- ion to Fe(OH)2(s). Explain why the addition of S2- ion to Cr(OH)3(s) does not result in the formation of Cr2S3(s).

    		•