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

The molecule having the smallest bond angle is

(1) H₂O

(2) H₂S

(3) H₂Te

(4) H₂Se

The correct statement regarding H₃PO₃ is:

1. Each hydrogen atom is attached to oxygen.

2. Two hydrogen atoms are attached to oxygen atoms.

3. One atom of H is attached to oxygen.

4. None of the above.

Strong oxidising agent and strong reducing agents are respectively

(1) F₂, HI

(2) Cl₂, HCl

(3) Br₂,HBr

(4) I₂, HF

Oxide of a non-metal possesses the following characterstics.

(i) It is both a proton donor and proton acceptor

(ii) It is poor conductor of electricity

(iii) It reacts readily with basic and acidic oxides

(iv) It oxidises Fe at boiling point.

The oxide is

(1) H₂O

(2) CO₂

(3) H₂O₂

(4) NO