Which of the following compound does not exist?

1. XeOF₄

2. NeF₂

3. XeF₂

4. XeF₆ 

Which of the following hydrides is the most acidic?

1. H₂Te

2. H₂Se

3. H₂O

4. H₂S

P forms multiple bonds in POCl₃ by using

1. $p\mathrm{\pi }-\mathrm{p\pi }$

2. $d\mathrm{\pi }-\mathrm{d\pi }$

3. $p\mathrm{\pi }-\mathrm{d\pi }$

4. None of the above.

Which of the following statements about phosphorus is false?
1. It is non-metal.
2. It exists as a tetrahedral molecular solid.
3. It is less reactive than nitrogen.
4. P-P bond is much weaker than $N\equiv N$ bond.

The basicity of the acids H₃PO₂, H₃PO₃, H₃PO₄  and H₄P₂O₇  are, respectively:

1. 1 , 2 , 3 , 7
2. 2 , 3 , 4 , 7
3. 1 , 2 , 3 , 4
4. 1 , 2 , 3 , 5

Which of the following acids is the strongest?
1. H₃PO₂ 
2. H₃PO₃ 
3. H₄P₂O₇ 
4. H₃PO₄ 

The element that does not form pentoxide is:

1. As
2. Sb
3. Bi
4. P

The compound among the following with the lowest pK_a value is?

1. H₂O

2. H₂S

3. H₂Se

4. H₂Te

The oxide of a non-metal possesses the following characteristics:

The formula for oxide is:

1. H₂O

2. CO₂

3. H₂O₂

4. NO

Which of the following hydrides is the least poisonous?

1. ${\mathrm{NH}}_3$

2. ${\mathrm{PH}}_3$

3. ${\mathrm{AsH}}_3$

4. ${\mathrm{SbH}}_3$