The number of $\mathrm{Cl}=\mathrm{O}$ bonds in perchloric acid is:

1.	4	2.	5
3.	2	4.	3

The reaction of NO with ${\mathrm{N}}_2{\mathrm{O}}_4$ at 250 K gives :

The products obtained when chlorine gas reacts with cold and dilute aqueous NaOH are:
1. Cl^– and ClO^–
2. Cl^– and ClO₂^–
3. ClO^– and ClO₃^–
4. ClO₃^– and ClO₃^–

Among the following oxoacids, the correct decreasing order of acid strength is:

1. ${\mathrm{HClO}}_4>\mathrm{HOCl}>{\mathrm{HClO}}_2>{\mathrm{HClO}}_3$

2. ${\mathrm{HClO}}_4>{\mathrm{HClO}}_3>{\mathrm{HClO}}_2>\mathrm{HOCl}$

3. ${\mathrm{HClO}}_2>{\mathrm{HClO}}_4>{\mathrm{HClO}}_3>\mathrm{HOCl}$

4. $\mathrm{HOCl}>{\mathrm{HClO}}_2>{\mathrm{HClO}}_3>{\mathrm{HClO}}_4$

Which of the following is the wrong statement?

1. Ozone is violet-black in solid-state

2. Ozone is paramagnetic gas

3. ONCl and ONO^–are not isoelectronic

4. O₃ molecule is bent 

The wrong statement among the following is-

Choose the incorrect statement among the following statements regarding the sulphur. 

The structure of IF₇ is :

1. Square pyramidal

2. Trigonal bipyramidal

3. Octahedral

4. Pentagonal bipyramidal

The most reactive species among the following is:

1. ${\mathrm{Cl}}_2$

2. ${\mathrm{Br}}_2$

3. ${\mathrm{I}}_2$

4. ICI

The element having the highest boiling point among the following is: