Short Answer TypeExplain the following:
(i) Boron has high melting and boiling points.
(ii) Aluminium is a good reducing agent.
Long Answer TypeDiscuss the characteristics of Group-13 elements in terms of metallic character and their tendency to exhibit inert pair effect.
Short Answer TypeBoron chloride exists a monomer while in the same group anhydrous, AlCl3 exists as a dimer?
White fumes appear around the bottle of anhydrous aluminium chloride.
Or
Why aluminium chloride in air?
Long Answer TypeSuggest a reason why the B - F bond lengths in BF3 (130 pm) and 
(143 pm) differ?
Or
Why B - F bond length in BF3 is smaller than the expected value?
Short Answer TypeIf B – Cl bond has a dipole moment, why does BCl3 has zero dipole moment ?
B and Cl have different electronegativities and chlorine (E.N. = 3.00) is more electronegative than B(E.N. = 2.00). As a result B – Cl bond is polar and hence has a finite dipole moment. Now BCl3 is a planar molecule in which the three B – Cl bonds are inclined at an angle of 120°. Therefore, the resultant of two B – Cl bonds in cancelled by equal and opposite dipole moment of the bond B – Cl bond as shown.
Hence overall dipole moment of BCl3 is zero.
. Assign the hybridization of boron in these species ?
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