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QuestionChemistry

Draw the Lewis structure for the polyatomic hydroperoxyl HO^2−anion. Be sure to include all resonance structures that satisfy the octet rule.
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Step 1:
: Identify the number of valence electrons in the hydroperoxyl anion (HO$_2^-$).

The hydroperoxyl anion consists of one oxygen atom, one hydrogen atom, and one negative charge. Since oxygen is in group 6, it has 6 valence electrons. Hydrogen is in group 1 and has 1 valence electron. To account for the extra negative charge, we add one more electron. In total, there are 6 (from O) + 1 (from H) + 1 (extra electron) = 8 valence electrons.

Step 2:
: Place the atoms in a reasonable initial structure.

Draw a central oxygen atom with a single bond to the hydrogen atom and a single bond to the second oxygen atom. This results in: ``` H-O-O: ```

Step 3:
: Distribute the remaining electrons to satisfy the octet rule.

Add the remaining electrons as lone pairs on the oxygen atoms. Since there are 8 valence electrons, we need to place 6 electrons as lone pairs. The resulting structure is: ``` H-O:-O: ```

Step 4:
: Check for formal charges.

Calculate the formal charge for each atom by: For the left oxygen atom: - V = 6 (valence electrons for oxygen) - L = 4 (lone pair electrons) - B = 2 (bonding electrons) For the right oxygen atom: - V = 6 (valence electrons for oxygen) - L = 6 (lone pair electrons) - B = 2 (bonding electrons)

Step 5:
: Draw resonance structures.

Since the formal charge on the left oxygen atom is + 2, we can move one lone pair electron to the neighboring oxygen atom to reduce its formal charge. This results in a double bond between the oxygen atoms and a formal charge of - 1 on the left oxygen atom and + 1 on the right oxygen atom. ``` H-O=O: :O-O: ```

Step 6:
: Check for a net dipole moment.

Since the formal charges are not equally distributed, there will be a net dipole moment.

Final Answer

The Lewis structure for the hydroperoxyl anion (HO$_2^-$) is: ``` H-O=O: :O-O: ``` These two resonance structures satisfy the octet rule and represent the hydroperoxyl anion.