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

(A) 1,2,3,7

(B) 2,3,4,7

(C) 1,2,3,4

(D) 1,2,3,5

The correct order of decreasing Lewis acid strength of trichlorides of group 15 elements is

$\left(A\right)<mspace\; width="1em"></mspace>AsC{l}_3>PC{l}_3>BiC{l}_3>SbC{l}_3$
$\left(B\right)PC{l}_3>AsC{l}_3>SbC{l}_3>BiC{l}_3$
$\left(C\right)<mspace\; width="1em"></mspace>NC{l}_3>PC{l}_3>AsC{l}_3>SbC{l}_3$
$\left(D\right)SbC{l}_3>BiC{l}_3>PC{l}_3>AsC{l}_3$

Which of the following flourides has the least capacity as fluoride ion acceptor

(1)AsF₅

(2) SbF₅

(3) PF₅

(4) None of these

The ionic character of H-X is highest in

(1) HBr

(2) HI

(3) HF

(4)HCl

The strongest acid is

(1) H₃PO₂ 

(2) H₃PO₃ 

(3) H₄P₂O₇ 

(4) H₃PO₄ 

Which of the following HY(hydra-acid of halogen) is the strongest acid, best reducing agent, is the least stable and is easily oxidised

(1) HF

(2) HCl

(3) HBr

(4) HI

The 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

Why does fluorine not produce oxyacids?

1. It is most electronegative

2. It is the most powerful oxidising agent

3. It has vacant d- orbitals

4. None of the above

Which is correct order of basic strength

(A) $OC{l}^{-}>Cl{O}_2^{-}>Cl{O}_3^{-}>Cl{O}_4^{-}$

(B) $Cl{O}_4^{-}>Cl{O}_3^{-}>Cl{O}_2^{-}>Cl{O}^{-}$

(C) $Cl{O}_3^{-}>Cl{O}_4^{-}>Cl{O}_2^{-}>Cl{O}^{-}$

(D) None of these

Which of the following does not form stable pentoxide

1. As

2. Sb

3. Bi

4. P