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Occurrence, Electronic Configuration, Atomic and Ionic Radii, Ionisation Enthalpy, Electron Gain Enthalpy, Electronegativity, Physical Properties and Chemical Properties (Oxidation states and trends in chemical reactivity and Anomalous behaviour of oxygen)
Account for the following :
There is large difference between the melting and boiling points of oxygen and sulphur.
Arrange the following in the order of property indicated for each set:
F2, Cl2, Br2, I2 - increasing bond dissociation enthalpy.
Explain why inspite of nearly the same electronegativity, oxygen forms hydrogen bonding while chlorine does not.
The HNH angle value is higher than HPH, HAsH and HSbH angles. Why? [Hint: Can be explained on the basis of sp3 hybridisation in NH3 and only s−p bonding between hydrogen and other elements of the group].
a. Explain the trends in the following properties with reference to group 16:
1 Atomic radii and ionic radii
3 ionisation enthalpy
b. In the electolysis of AgNO3 solution 0.7g of Ag is deposited after a certain period of time. Calulate the quantity of electricity required in coulomb. (Molar mass of Ag is 107.9g mol-1)
c. Define Osmosis
Give reasons for the following :
H2Te is the strongest reducing agent amongst all the hydrides of Group 16 elements.
Justify the placement of O, S, Se, Te and Po in the same group of the periodic table in terms of electronic configuration, oxidation state and hydride formation.
Knowing the electron gain enthalpy values for O → O− and O → O2− as −141 and 702 kJ mol−1 respectively, how can you account for the formation of a large number of oxides having O2− species and not O−? (Hint: Consider lattice energy factor in the formation of compounds).