Question

Consider the following reaction:
 \({2HSO_4^ −}_{(aq)}\xrightarrow[(2)Hydrolysis]{(1)Electrolysis}  2HSO_4^− + 2H^+ + A\)
The dihedral angle in product A in its solid phase at 110 K is :

• A. 104°
• B. 111.5°
• C. 90.2°
• D. 111.0°

Answer 1

The Correct Option is C

To solve this question, we need to identify the reaction taking place and the nature of product A. The reaction given is:

2HSO_4^- \xrightarrow[(2) \text{Hydrolysis}]{(1) \text{Electrolysis}} 2HSO_4^- + 2H^+ + A

This reaction involves the electrolysis and subsequent hydrolysis, resulting in the production of a gaseous compound typically formed in such reactions. The most likely product A formed during the electrolysis of hydrogen sulfate ions HSO_4^-\ is sulfur trioxide (SO_3).

In its solid phase at very low temperatures, solid SO_3\ exists in a polymeric form, which determines the dihedral angles within its crystalline structure. According to the question, the dihedral angle in product A is asked specifically at 110 K.

In solid form, SO_3\ is known to have dihedral angles of about 90.2° due to its particular orientation in the solid-state lattice structure.

Therefore, the correct answer to the question is the option "90.2°". This makes solid-state orientation a key factor for the dihedral angle determination.

The other options (104°, 111.5°, and 111.0°) typically correspond to bond angles or dihedral angles in different molecules or conditions, hence not applicable here for solid SO_3\ at 110 K.