1. Which of the following is most volatile?[MOE 2062]
(a) Benzene (C6H6) is most volatile as it has the weakest intermolecular forces (only London dispersion forces). 2. Which of the following compounds has two lone pairs of electron and 2 bond pairs?[MOE 2060]
(b) H2O has 2 bond pairs (O-H) and 2 lone pairs on oxygen (AX2E2). 3. Which does not obey octet rule?[IOM 2008, MOE 2003]
(a) PF5 has 10 electrons around P (violates octet rule). 4. An element forms XCl3, X2O5, XO2 but can't form XCl5. The element may be[B.E. 2009]
(a) Nitrogen forms NCl3, N2O5, NO2 but not NCl5 due to absence of d-orbitals. 5. Which of the following elements shows sp, sp2 and sp3 hybridization?[MOE 2002]
- Carbon
- Silicon
- Phosphorus
- Boron
(a) Carbon shows all three: sp (C2H2), sp2 (C2H4), sp3 (CH4). 6. Which of the following is incorrect?[MOE 2002]
- σ bond is stronger than π bond
- Carbon-carbon double bond is stronger than single bond
- Double bond is shorter than single bond
- Covalent bond is weaker than hydrogen bond
(d) Covalent bonds (∼100-400 kJ/mol) are much stronger than H-bonds (∼5-30 kJ/mol). 7. Which of the following is non-planar?[MOE 2002]
(d) PCl5 has trigonal bipyramidal geometry (non-planar). 8. The valency of C in CO is 2. The valency of C in CO2 is 4. The valency of C in acetylene is[MOE 2002]
(b) In C2H2, carbon forms 4 bonds (1 triple + 1 single). 9. When s and p orbitals hybridise, then[IOM 1997]
- 2 orbitals are formed
- 4 orbitals perpendicular and tetrahedral are formed
- 3 orbitals are formed
- Only one orbital is formed
(b) sp3 hybridization forms 4 tetrahedral orbitals (e.g., CH4). 10. The electronic configuration of an element is 2, 8, 1. Which of the following statement is true?[IOM 1996]
- It is diatomic
- It is non-metal
- It is a transitional metal
- It forms basic oxides
(d) Element is Na (2,8,1) which forms basic oxide Na2O. 11. The no. of 'σ' and 'π' bonds in 'C' atoms of CaC2 is[BPKIHS 2006]
(a) CaC2 has [C≡C]2- with 1σ and 2π bonds between carbons. 12. Which of the following is a pseudo halide?[BPKIHS 1994]
(b) CN- behaves like halides (pseudo-halogen). 13. The shape of XeF2 molecule is[BPKIHS]
- Linear
- Triangular planar
- Pyramidal
- Square planar
(a) XeF2 has linear shape (AX2E3 with 3 lone pairs). 14. Which of the following hybridization is seen in CO2 molecule?[BPKIHS 2006]
(a) CO2 has sp hybridization (linear geometry). 15. Which of the following is not true about CCl4?[BPKIHS 2005]
- It possess tetrahedral structure
- It is polar in nature
- It has no non-bonded electrons on carbon
- It is an organic compound
(b) CCl4 is non-polar due to symmetrical tetrahedral shape. 16. The hybridization of H2O is
(b) H2O has sp3 hybridization (tetrahedral electron geometry). - Ionic bond
- Covalent bond
- Co-ordinate bond
- Covalent and co-ordinate bond
(b) Diamond has 3D network of covalent C-C bonds. 18. Shape of Ammonia is[BPKIHS]
- Pyramidal
- Tetrahedral
- Coplanar
- Trigonal
(a) NH3 has pyramidal shape (AX3E with 1 lone pair). 