Question

Select correct description of a bromonium ion. a. a cationic molecule with the general formula R − Br + b. a cationic molecule with the general formula R − Br − Br + c. an ion with the formula Br + 2 d. a cationic molecule containing a three‑membered ring with the general formula R − Br + − R ′ an ion with the formula Br − 3

Answer 1

Answer:

• A bromonium ion is: a cationic molecule containing a three‑membered ring with the general form  R − Br⁺ − R'

Explanation:

A bromonium ion is a positive ion (cation) formed by a bromine atom attached to two carbon atoms.

The positive charge is on the bromine atom.

Regularly, a Br atom has 7 valence electrons. That is when Br is neutral.

When a Br atom forms a covalent bond with a C atom, they share one electron each and thus Br completes its octet: 8 electrons.

When a Br atom combine with two different C atoms, now Br is sharing one additional electron, which leaves it with and excess of positive charge. That is why the Br atom in the bromonium ion has a positive charge, making it a cationic species.

The two C atoms, bonded to each other and to the Br⁺ form a cyclic species of this kind:

   − C −    C −

       \       /

         Br⁺

Hence, it is a ring.