Which of the following oxide is most acidic

(A) Na₂O

(B) Al₂O₃

(C) P₂O₅

(D) SO₃

Which among the following is least acidic

(1) P₄O₆ 

(2) P₄O₁₀ 

(3) As₄O₆ 

(4) As₄O₁₀ 

Moist ammonia gas is dried over

(A) P₂O₅

(B) Anhydrous CaCl₂

(C)Quick lime

(D)Conc. H₂SO₄

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 flourides has the least capacity as fluoride ion acceptor

(A)AsF₅

(B) SbF₅

(C) PF₅

(D) None of these

The ionic character of H-X is highest in

(A) HBr

(B) HI

(C) HF

(D)HCl

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

Strength of halogen acids, HF, HCl, HBr and HI varies in the order

(1) HF>HCl>HBr>HI

(2)HF>HBr>HI>HCl

(3) HBr>HI>HCl>HF

(4) HI>HBr>HCl>HF