Level – 1
1. Which among the following has highest boiling point & why?
H2 , He , Ne , Xe , CH4
2. Explain why bond angle of NH3 is greater than NF3 while bond angle of PH3 is less than that of PF3
3. Explain dipole moment of NH3 is more than that of NF3 ?
4. Anhydrous AlCl3 is covalent from the data given below, predict whether it would remain covalent or become ionic in aqueous solution.
Ionization energy of Al = 5137 kJ/mol
ΔHhydration (Al3+) = – 4665 kJ/mol
ΔHhydration (Cl–) = – 381 kJ/mol
5. In (CH3)3N nitrogen is sp3 hybridized whereas in (SiH3)3N it is sp2 hybridised why?
6. Though Cs is most electropositive element in periodic table Li has highest oxidation potential why?
7. Though Li+ ion is smaller than Cs+ ion its mobility in aqueous solution is more than Cs+ ion.
8. On the basis of ground state electronic configuration arrange the following
molecules in increasing N – N bond length order.
NaN2 , N2
9. CaCO3 dissolves in HCl but not in water.
10. In case of triatomic molecules SO2 & H2O have considerable dipole moment, but no such moment is possible for CO2 molecule.