Draw the Lewis structure for BrO3 -

General
1

Draw the Lewis structure for BrO3 -.

2

Draw the Lewis structure for BrO3 -

Answer: Drawing the Lewis structure for the bromate ion, \text{BrO}_3^- involves several steps to ensure all atoms fulfill the octet rule and the structure accurately represents the ion’s electron configuration.

Steps to Draw the Lewis Structure for BrO3 -

  1. Count the Total Number of Valence Electrons:

    • Bromine (Br) has 7 valence electrons.
    • Each Oxygen (O) atom has 6 valence electrons, and there are 3 oxygen atoms.
    • The negative charge adds one extra electron.

    Total valence electrons = 7 + 3 \times 6 + 1 = 26 electrons.

  2. Determine the Central Atom:

    • In most cases, the least electronegative atom (excluding hydrogen) is the central atom. Here, bromine is less electronegative than oxygen, so bromine will be the central atom.

  3. Arrange the Atoms and Distribute Electrons:

    • Place bromine in the center and surround it with three oxygen atoms.
    • Connect each oxygen atom to the bromine atom with a single bond.

  4. Distribute Remaining Electrons:

    • After forming the initial bonds (each bond represents 2 electrons), 6 electrons are used, leaving us with ( 26 - 6 = 20 ) electrons.
    • Distribute the remaining 20 electrons among the oxygen atoms to complete their octets. Each oxygen requires 8 electrons in total, including those in bonds.
    • Initially, each oxygen will get 6 additional electrons (since each has 2 electrons already in the bond with bromine). But, we still need to consider the octet rule for every atom involved.

  5. Ensure the Octet Rule is Satisfied:

    • Bromine, being in period 4, can have more than 8 electrons due to the availability of d-orbitals.
    • Typically, a reasonable Lewis structure might show double bonds or even resonance to account for the extra electrons and further stabilization.
    • This means we can place a double bond on one of the oxygen atoms.

Possible Lewis Structures

  1. Single Bonds with Formal Charges:

    • Place lone pairs to satisfy the octet for each oxygen atom.
    • This may result in formal charges where assigned. Double bonds might help in minimizing these formal charges.

  2. Resonance Structures:

    • The bromate ion can have resonance structures, where the double bond can shift between the oxygen atoms to delocalize the charge, providing overall stability.

Lewis Structure Visualization:

To simplify, let’s consider one overview where formal charges and resonance contribute equally.

  • Draw a central bromine atom.
  • Attach three oxygen atoms by single bonds.
  • Add lone pairs to each oxygen atom until each has an octet.
  • You should have added 20 lone electrons.
  • Place the extra electrons on bromine to complete all electrons.
  • Adjust one of the bonds to be double to minimize formal charge where needed.

Example structure after minimal bonding:

       :O:
       ||
   Br - O -
       ||
       :O:
  • The above shows a central Br with one single bond and resonance structures.

Final Structure(s):

Resonance involving 3 forms:

    ..                   ..                    ..
:O::Br::O-    ↔    :O::Br::O-   ↔  :O::Br::O.
 .       .            .      .           .
      ::O-                 ::O.                   :O-.

Conclusion:

The true structure is a hybrid of the resonance forms, leading to an effectively robust and well-distributed electron density. Applying the octet rule, ensure bromine has expanded octet ability in accordance with bond shifts.

This balanced structure offers the most stable representation, ensuring everyone is properly acquainted with Lewis structures and resonance representations.

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