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

Flourine does not form oxyacids because

(1) It is most electronegative

(2) It is the most powerful oxidising agent

(3) It has vacant d- orbitals

(4) None of these

The element that does not form pentoxide is:

1. As
2. Sb
3. Bi
4. P

F₂ reacts with dilute NaOH to give oxygen difluroide of the formula

(1) F₂O

(2) OF₂

(3) F₂O₂

(4) F₂O₃

Which of the following oxyacids of chlorine is having least tendency to get oxidized?

(1) HOCl

(2) HClO₂

(3) HClO₃

(4) HClO₄

Which of the following is most basic

(1) F^-

(2) Cl^-

(3) Br^-

(4) $I^{\mathit{-}}$

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

1. H₂O

2. H₂S

3. H₂Se

4. H₂Te

The shape of $Cl{O}_3^{-}$ is

(A) Tetrahedral

(B) Triangular planer

(C) Triangular pyramid

(D) Planer

Oxygen does not form OF₆ because

(A) It has a small size

(B) There are no vacant d- orbitals available

(C) It has high ionisation energy

(D) It has large size