The correct order of bond dissociation enthalpy of halogens is :

1. ${\mathrm{Cl}}_2>{\mathrm{F}}_2>{\mathrm{Br}}_2>{\mathrm{I}}_2$

2. ${\mathrm{I}}_2>{\mathrm{Br}}_2>{\mathrm{Cl}}_2>{\mathrm{F}}_2$

3. ${\mathrm{Cl}}_2>{\mathrm{Br}}_2>{\mathrm{F}}_2>{\mathrm{I}}_2$

4. ${\mathrm{F}}_2>{\mathrm{Cl}}_2>{\mathrm{Br}}_2>{\mathrm{I}}_2$

Aqua regia is used for dissolving noble metals (Au, pt, etc.). The gas evolved in this process is: 

1. N₂O₅

2. N₂O₃ 

3. N₂ 

4. NO 

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

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^–

The most reactive species among the following is:

1. ${\mathrm{Cl}}_2$

2. ${\mathrm{Br}}_2$

3. ${\mathrm{I}}_2$

4. ICI

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

The structure of IF₇ is :

1. Square pyramidal

2. Trigonal bipyramidal

3. Octahedral

4. Pentagonal bipyramidal

In which of the following arrangements, the sequence is not strictly according to the property written against it?