Question

chemistry students are learning about lewis structures. their instructor asks them to draw lewis structures for carbon dioxide using both electron dots and bonds to show bonding relationships. which of the following lewis structures are correct? select all that apply :ö::c::ö: :ö::c::o: :ö=c=ö: ö=c=ö: i ii iii iv □ iii □ i □ iv □ ii

Explanation:

• Structure I: In Lewis structures, carbon dioxide (\(CO_2\)) has carbon in the center. Each oxygen has 6 valence electrons and carbon has 4. In this structure, using electron - dot notation, carbon forms double bonds (represented by two pairs of dots) with each oxygen. The total number of valence electrons is \(4+(6\times2)=16\). Each oxygen has 6 non - bonding electrons (3 pairs) and 2 bonding electrons (in a double bond), and carbon has 4 bonding electrons. This structure is correct.
• Structure II: The oxygen on the right has only 5 valence electrons shown (3 non - bonding pairs and 1 bonding electron), which is incorrect as oxygen should have 6 valence electrons.
• Structure III: Using the bond notation (where a line represents a pair of electrons), carbon forms double bonds with each oxygen. Each oxygen has 6 non - bonding electrons (3 pairs) and carbon has no non - bonding electrons. The total valence electrons accounted for: each double bond has 2 pairs of electrons (4 electrons per double bond), and each oxygen has 6 non - bonding electrons. \(2\times4+(6\times2)=8 + 12=16\). This structure is correct.
• Structure IV: The oxygen atoms do not have their non - bonding electrons shown. In a proper Lewis structure, oxygen in \(CO_2\) should have 6 non - bonding electrons (3 pairs) around it. This structure is incorrect.

Answer:

I. \(:\ddot{O}::C::\ddot{O}:\)
III. \(:\ddot{O}=C=\ddot{O}:\)