The correct statements from the following are : Choose the correct answer from the options given below :
- (A), (B), (C) and (E) only
- (C) and (E) only
- (A), (C) and (E) only
- (A) and (C) only
Answer
(2) (C) and (E) only
Solution
(A): Ga (135 pm) < Al (143 pm) ∵ poor shielding by 3d electrons ⇒ order is Tl > In > Al > Ga > B ⇒ (A) false
(B): EN falls from B to Al, then rises slightly: Al (1.5) < Ga (1.6) < In (1.7) < Tl (1.8) ⇒ (B) false
(C): 2Al + 6HCl 2AlCl3 + 3H2; conc. HNO3 forms a thin oxide film ⇒ (C) true
(D): stable +1 state only for heavier members (Tl, inert pair effect); B and Al do not show it ⇒ (D) false
(E): six H2O use 3s, 3p and 3d orbitals of Al3+ ⇒ sp3d2, octahedral ⇒ (E) true
∴ (C) and (E) only
Answer: (2)