PH₃ forms bubbles when passed slowly through water but NH₃ gets dissolved in water, because: 

1.	NH3 forms an H-bond with water, so it is soluble but PH3 does not form an H-bond.
2.	NH3 does not form an H-bond with water, so it is soluble but PH3 does form an H-bond.
3.	NH3 and PH3 both form H-bond with water.
4.	NH3 and PH3 both do not form H-bond with water.

All the five bonds of PCl₅ are not equivalent because:

Nitrogen dioxide is paramagnetic in a gaseous state but diamagnetic in solid because:

The correct statement regarding the bond angle of H₂O and H₂S is:

1. Both have the same bond angle.

2. Bond angle of H₂O is larger than that of H₂S

3. Bond angle of H₂O is smaller than that of H₂S 

4. None of the above.

The chemical formula of oleum is - 

The correct increasing order of basic strength of hydrides:

1. BiH₃ \(\simeq \) SbH₃ < AsH₃ < PH₃ < NH₃ 
2.  BiH₃  > NH₃  > PH₃ > SbH₃ > AsH₃ 
3. SbH₃ < AsH₃ < PH₃ < NH₃ < BiH₃ 
4. AsH₃ > NH₃ > PH₃ > SbH₃ > BiH₃

The correct structure of pyrophosphoric acid is:

1.		2.
3.		4.

A balanced chemical equation for the reaction showing catalytic oxidation of NH₃ by atmospheric oxygen is:

An element that does not show allotropy is:
1. Nitrogen
2. Phosphorus
3. Antimony
4. Arsenic

The maximum covalency of nitrogen is:

1. 3

2. 5

3. 4

4. 6