Match List - I with List - II

List - I	List - II
(a) PCl5	(i) Square pyramidal
(b) SF6	(ii) Trigonal planar
(c) BrF5	(iii) Octahedral
(d) BF3	(iv) Trigonal bipyramidal

Choose the correct answer from the options given below 

To match the molecules in List-I with their correct molecular geometries in List-II, we can use the Valence Shell Electron Pair Repulsion (VSEPR) theory. The steric number (SN) helps determine the hybridization and molecular geometry of a molecule using the formula:

$\text{Steric Number (SN)}=\frac{1}{2}[V+M-C+A]$

where:
- $V$ = number of valence electrons of the central atom
- $M$ = number of monovalent atoms attached to the central atom
- $C$ = charge of the cation (if any)
- $A$ = charge of the anion (if any)

1. Analysis of (a) PCl₅ (Phosphorus pentachloride):
- Central atom is Phosphorus (P), which belongs to Group 15 and has $V=5$ valence electrons.
- There are 5 monovalent Chlorine (Cl) atoms attached ($M=5$).
- Calculating the steric number:
$\text{SN}=\frac{1}{2}(5+5)=5$
- Since the steric number is 5 with 5 bond pairs and 0 lone pairs, the hybridization is ${\text{sp}}^3\text{d}$ and the molecular geometry is Trigonal bipyramidal.
- Therefore, (a) matches with (iv).

2. Analysis of (b) SF₆ (Sulfur hexafluoride):
- Central atom is Sulfur (S), which belongs to Group 16 and has $V=6$ valence electrons.
- There are 6 monovalent Fluorine (F) atoms attached ($M=6$).
- Calculating the steric number:
$\text{SN}=\frac{1}{2}(6+6)=6$
- With a steric number of 6 consisting of 6 bond pairs and 0 lone pairs, the hybridization is ${\text{sp}}^3{\text{d}}^2$ and the molecular geometry is Octahedral.
- Therefore, (b) matches with (iii).

3. Analysis of (c) BrF₅ (Bromine pentafluoride):
- Central atom is Bromine (Br), which belongs to Group 17 and has $V=7$ valence electrons.
- There are 5 monovalent Fluorine (F) atoms attached ($M=5$).
- Calculating the steric number:
$\text{SN}=\frac{1}{2}(7+5)=6$
- Out of 6 electron pairs, 5 are bond pairs and 1 is a lone pair. This gives a hybridization of ${\text{sp}}^3{\text{d}}^2$ and a molecular shape of Square pyramidal.
- Therefore, (c) matches with (i).

4. Analysis of (d) BF₃ (Boron trifluoride):
- Central atom is Boron (B), which belongs to Group 13 and has $V=3$ valence electrons.
- There are 3 monovalent Fluorine (F) atoms attached ($M=3$).
- Calculating the steric number:
$\text{SN}=\frac{1}{2}(3+3)=3$
- With a steric number of 3 consisting of 3 bond pairs and 0 lone pairs, the hybridization is ${\text{sp}}^2$ and the molecular geometry is Trigonal planar.
- Therefore, (d) matches with (ii).

Combining all the matched pairs, we get:
- (a) → (iv)
- (b) → (iii)
- (c) → (i)
- (d) → (ii)

Thus, the correct option matching List-I with List-II is (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii).