The correct order of the boiling points of \(\mathrm{H}_2 \mathrm{O}, \mathrm{HF}, \text{ and} \ \mathrm{NH}_3\) is: 

1. HF > H₂O > NH₃

2. H₂O > HF > NH₃

3. NH₃ > HF > H₂O

4. NH₃ > H₂O > HF

In ${\mathrm{PO}}_4^{3-}$ ion, the formal charge on the oxygen atom of the P-O bond is : 

In ${\mathrm{NO}}_3^{-}$ ion, the number of bond pairs and lone pairs of electrons exhibited by nitrogen atom is:

1. 2, 2

2. 3, 1

3. 1, 3

4. 4, 0

Which species lacks tetrahedral geometry?

The number of $\mathrm{\pi }$ bonds and $\mathrm{\sigma }$ bonds in the following structure is :

The species that does not have unpaired electrons is:
 

In which of the following molecule/ion all the bonds are not equal?

Hydrogen bond will be strongest in : 

1. HCl

2. H₂O

3. HI

4. H₂S

If the electronic configuration of an element is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^{2}4{\mathrm{s}}^2$, the four electrons that participate in the chemical bond formation will be from :

The correct bond angle for \(\mathrm{sp}^2\) hybridization is:
1. \(90^\circ\)
2. \(120^\circ\)
3. \(180^\circ\)
4. \(109^\circ\)