The number and type of bonds between two carbon atoms in calcium carbide are 

1. One sigma, two pi

2. Two sigma, two pi 

3. One sigma, one pi 

4. Two sigma, one pi 

Which among the following does not contain a set of isoelectronic species?

1. $\mathrm{S}{{\mathrm{O}}_3}^{2-\mathrm{}}$, CO₃^2-,NO₃^-

2. ${\mathrm{CN}}^{-},<mspace\; width="1em"></mspace>{\mathrm{N}}_2,<mspace\; width="1em"></mspace>\mathrm{CO}$

3. ${\mathrm{BO}}_3^{3-}<mspace\; width="1em"></mspace>,<mspace\; width="1em"></mspace>{\mathrm{CO}}_3^{2-<mspace\; width="1em"></mspace>},\mathrm{N}{{\mathrm{O}}_3}^{-}$

4. ${\mathrm{PO}}_4^{3-},<mspace\; width="1em"></mspace>{\mathrm{SO}}_4^{2-},<mspace\; width="1em"></mspace>\mathrm{Cl}{{\mathrm{O}}_4}^{-}$

Which of the following molecules/ions does not contain unpaired electrons?

(1) O${}_2^{<mspace\; width="1em"></mspace>2-}$

(2) ${{\mathrm{C}}_2}^{-}$

(3) $N_2^{+}$

(4) O${}_2$

A molecule or ion that has an unequal bond length is:

Which of the following species exhibits the diamagnetic behaviour?

(1) O${}_2^{<mspace\; width="1em"></mspace>+}$

(2) O${}_2$

(3) NO

(4) O${}_2^{<mspace\; width="1em"></mspace>2-}$

The correct increasing order of the polarizing power of the cationic species  ${\mathrm{K}}^{+},<mspace\; width="1em"></mspace>{\mathrm{Ca}}^{2+},<mspace\; width="1em"></mspace>{\mathrm{Mg}}^{2+},<mspace\; width="1em"></mspace>{\mathrm{Be}}^{2+}$is: 

1. ${\mathrm{Be}}^{2+}<{\mathrm{K}}^{+}<{\mathrm{Ca}}^{2+}<{\mathrm{Mg}}^{2+}$

2. ${\mathrm{K}}^{+}<{\mathrm{Ca}}^{2+}<{\mathrm{Mg}}^{2+}<{\mathrm{Be}}^{2+}$

3. ${\mathrm{Ca}}^{2+}<{\mathrm{Mg}}^{2+}<{\mathrm{Be}}^{2+}<{\mathrm{K}}^{+}$

4. ${\mathrm{Mg}}^{2+}<{\mathrm{Be}}^{2+}<{\mathrm{K}}^{+}<{\mathrm{Ca}}^{2+}$

Which one of the following pair of species have the same bond order?

(1) CN${}^{-}$ and NO${}^{+}$

(2) CN and CN${}^{+}$

(3) O${}_2^{<mspace\; width="1em"></mspace>-}$ and CN${}^{-}$ 

(4) NO${}^{+}$ and CN${}^{+}$

Among the following, the maximum covalent character is shown by which compound:

1. ${\mathrm{MgCl}}_2$

2.$$ ${\mathrm{FeCl}}_2$

3. ${\mathrm{AlCl}}_3$

4. ${\mathrm{SnCl}}_2$

Match the compounds of Xe in column I with the molecular structure in column II.

   Column-I       Column-II

(a) ${\mathrm{XeF}}_2$       (i) Square planar

(b) ${\mathrm{XeF}}_4$     (ii) Linear

(c) ${\mathrm{XeO}}_3$      (iii) Square pyramidal

(d) ${\mathrm{XeOF}}_4$    (iv) Pyramidal

(1) (a)-(ii) (b)-(i) (c)-(iii) (d)-(iv)

(2) (a)-(ii) (b)-(iv) (c)-(iii) (d)-(i)

(3) (a)-(ii) (b)-(iii) (c)-(i) (d)-(iv)

(4) (a)-(ii) (b)-(i) (c)-(iv) (d)-(iii)

The correct relationship for the bond angle of water and dimethyl ether $\left({\mathrm{CH}}_3-\underset{..}{\overset{..}{\mathrm{O}}}-{\mathrm{CH}}_3\right)$ is: