Which of the following does not form stable pentoxide

1. As

2. Sb

3. Bi

4. P

Which is the correct order order of decreasing boiling point of azeotropic mixtures HX-H₂O

(1) HI,HBr,HF,HCl

(2) HI,HCl,HBr,HF

(3) HF,HCl,HBr,HI

(4) HCl,HF,HBr,HI

F₂ reacts with dilute NaOH to give oxygen difluroide. The formula is

(1) F₂O

(2) OF₂

(3) F₂O₂

(4) F₂O₃

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

(1) HOCl

(2) HClO₂

(3) HClO₃

(4) HClO₄

Which of the following is most basic

(1) F^-

(2) Cl^-

(3) Br^-

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

Of the hydrides, $H_{2}O, H_{2}Se, and H_{2}Te$, the one which has the smallest pK_a value is

1. H₂O

2. H₂S

3. H₂Se

4. H₂Te

The shape of $Cl{O}_3^{-}$ is

(1) Tetrahedral

(2) Triangular planer

(3) Triangular pyramid

(4) Planer

Which reaction can not be used for the preparation of halogen acid

$\left(A\right) 2KBr +H_{2}S{O}_4(conc.) \to K_{2}S{O}_4 +2HBr$
$\left(B\right) NaCl +H_{2}S{O}_4(conc.) \to NaHS{O}_4 +HCl$
$\left(C\right) NaHS{O}_4 +NaCl \to N{a}_{2}S{O}_4 +HCl$
$\left(D\right) Ca{F}_2 +H_{2}S{O}_4(conc.) \to CaS{O}_4 +2HF$

An element (X) forms compounds of the formula $XC{l}_3, X_2{O}_5 and C{a}_3{X}_2,$but does not form X$C{l}_5$. Which of the following is the element

(1) B

(2) Al

(3) N

(4) P

Oxygen does not form OF₆ because

1. It has a small size

2. There are no vacant d- orbitals available

3.  It has high ionization energy

4. It has a large size