Chemistry - CHEMICAL BONDING Question with Solution | TestHub

(i) Number of species acting as Lewis acid (p):

Lewis acid = electron pair acceptor, often electron-deficient or with empty orbitals.

SiF₄: Si has incomplete octet → Lewis acid

H₂O: Has lone pairs, acts as Lewis base → No

PCl₅: P can expand octet, accepts pairs → Lewis acid

NH₃: Lone pairs on N → Lewis base → No

BF₃: Electron-deficient B → Lewis acid

p = 3

(ii) Number of species with lone pair on central atom (q):

Check lone pairs on central atoms:

SiF₄: Si has no lone pair → No

H₂O: O has 2 lone pairs → Yes

PCl₅: P has no lone pair → No

NH₃: N has 1 lone pair → Yes

BF₃: B has no lone pair → No

q = 2

(iii) Number of species in which underlined atom has highest oxidation number (r):

Oxidation states:

Si in SiF₄: +4 (max for Si) → Yes

O in H₂O: –2 (not max, O can be +2 in some compounds) → No

P in PCl₅: +5 (max for P) → Yes

N in NH₃: –3 (not max, N can be +5) → No

B in BF₃: +3 (max for B) → Yes

r = 3

Ans. p q r = 3 2 3 → 323