Question

Which of the following statements is incorrect regarding physisorption?
It occurs because of the van der Waal forces
Liquefiable gases are adsorbed more easily
Enthalpy of adsorption $(\Delta {H_{adsorption}})$is high and negative
Enthalpy of adsorption $(\Delta {H_{adsorption}})$ is low and positive

Answer 1

Hint : Isomerism is the phenomenon in which two or more substances having the same molecular formula but differing in their either chemical structures of the spatial arrangement of the atoms. Such structures are known as isomers.

Step-by-step explanation:
Step 1:
There are two types of isomers,
Structural isomers – Two or more complex compounds having the same molecular formula possess different structural arrangements are said to be structural isomers.
Geometrical isomers – When the different isomers differ in the spatial positions of the ligands around the central metal atom, they are said to be geometrical isomers.
Step 2
There are two types of coordination compounds:
Four coordination compounds – which takes either a square planar geometry or tetrahedral geometry.
Six coordination compounds – which takes an octahedral geometry.
Step 3
Octahedral complexes containing only monodentate ligand of the type $[M{a_2}{b_2}{c_2}],[M{a_2}{b_2}cd],[M{a_2}bcde],[Mabcdef]$ are optically active as they do not possess any element of symmetry.
In the octahedral complexes having one or more symmetrical bidentate chelating ligands of the type:
${[M{(AA)_3}]^{n \pm }}$- The three symmetrical bidentate ligands AA are coordinated to the central metal atom M. Such complexes are optically active as they do not possess any element of symmetry.
${[M{(AA)_2}{a_2}]^{n \pm }}$& ${[M{(AA)_2}ab]^{n \pm }}$- In this case, the two symmetrical bidentate chelating ligands AA and two monodentate ligands a and b are coordinated to the central metal atom M which can also exhibit optical isomerism.
${[M{a_3}{b_3}]^{n \pm }}$- For this type of compound, there can be three identical ligands that can occupy one face of the octahedron and the isomers can be termed as facial or fac. In this type of isomers, any two identical ligands occupy the adjacent or cis position to each other.

Hence, option b) $[Co{(N{H_3})_3}{(N{O_2})_3}]$ and option c) $[Co{(N{H_3})_3}{(CO)_3}]Cl$having the octahedral geometry of the type ${[M{a_3}{b_3}]^{}}$shown facial isomerism.

Note : Facial isomers and meridional isomers are two terms that often get confused. When the three ligands occupy the same face of the octahedron it is said to be facial isomer whereas when the three ligands and the central metal ion are in the same plane it is said to be meridional.