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: