Question

The electronegativity of a group 13 element 'E' is same as that of Ge (on Pauling scale and upto one decimal point). The CORRECT statements about \( E^{3+} \) are:
A. It can act as a reducing agent.
B. It can act as an oxidizing agent.
C. \( E^{3+} \) is more stable than \( E^+ \).
D. The standard electrode potential value for \( E^{3+}/E \) is positive.
Choose the correct answer from the options given below:

• A. A and C Only
• B. B and C Only
• C. B and D Only
• D. A and D Only

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Electronegativities in Group 13 show an unusual trend: B(2.0), Al(1.5), Ga(1.6), In(1.7), Tl(1.8). Germanium (Ge) has an electronegativity of 1.8. Thus, element 'E' is Thallium (Tl).

Step 2: Key Formula or Approach:
Inert pair effect: For heavy p-block elements (like Tl), the +1 oxidation state is more stable than the +3 state because the s-electrons are reluctant to participate in bonding.

Step 3: Detailed Explanation:
Identify E = Tl.
- (C) False: For Tl, \( E^+ \) is more stable than \( E^{3+} \) due to inert pair effect.
- (B) True: Since \( Tl^{3+} \) is unstable, it readily gains 2 electrons to become \( Tl^+ \), acting as a strong oxidizing agent.
- (A) False: Reducing agents lose electrons. \( Tl^{3+} \) won't lose more easily.
- (D) True: Standard reduction potentials for \( Tl^{3+} \to Tl \) or \( Tl^{3+} \to Tl^+ \) are positive, indicating spontaneous reduction.
Therefore, B and D are correct.

Step 4: Final Answer:
Statements B and D are correct.