The number of $\mathrm{\sigma }$ and $\mathrm{\pi }$ bonds between two carbon atoms in calcium carbide are

• $\mathrm{one} \mathrm{\sigma }, \mathrm{one} \mathrm{\pi }$

• $\mathrm{one} \mathrm{\sigma }, \mathrm{two} \mathrm{\pi }$

• $\mathrm{two} \mathrm{\sigma }, \mathrm{one} \mathrm{\pi }$

• $\mathrm{one} \mathrm{\sigma }, 1\frac{1}{2}\mathrm{\pi }$

An element X belongs to fourth period and fifteenth group of the periodic table. Which of the following statements is true?

• It has completely filled s-orbital and a partially filled d-orbital.

• It has completely filled s-and p -orbitals and a partially filled d-orbital.

• It has completely filled s- and p-orbitals and a half filled d-orbital.

• It has a half filled p -orbital and completely filled s-and d-orbitals.

Of the following molecules, which have shape similar to CO₂?

• HgCl₂

• SnCl₂

• C₂H₂

• NO₂

44.

The number of lone pairs of electrons on the central atoms of H₂O, SnCl₂, PCl₃ and XeF₂ respectively are

• 2, 1, 1, 3

• 2, 2, 1, 3

• 3, 1, 1, 2

• 2, 1, 2, 3

In the following compound, the number of sp-hybridised carbons are

CH₂=C=CH-CH(CN)-C≡CH

• 2

• 3

• 4

• 5

The correct order of decreasing H-C-H angle in the following molecule is

• I> II> III

• II> I> III

• III> II> I

• I> III> II

The correct order of decreasing length of the bond as indicated by the arrow in the following structures is

• I >II > III

• II > I > III

• III > II > I

• I > III > II

In SOCl₂, the Cl-S-Cl and Cl-S O bond angles are

• 130° and 115°

• 106° and 96°

• 107° and 108°

• 96° and 106°

In O₂ and H₂O₂ , the O-O bond lengths are 1.21 and 1.48 Å respectively. In ozone, the average O-O bond length is

• 1.28 Å

• 1.18 Å

• 1.44 Å

• 1.52 Å

In diborane, the number of electrons that accounts for bonding in the bridges is

• six

• two

• eight

• four