Question

chemistry semester 1 exam on level 25-26
which is the correct molecular structure for carbon dioxide, co₂ ?
options with molecular structures (o=s=o with lone pairs, o=c=o with lone pairs, c≡o: with lone pairs, o=c=o: with lone pairs)

Explanation:

Step1: Analyze the formula of \( CO_2 \)

Carbon dioxide has the formula \( CO_2 \), so the central atom should be \( C \), not \( S \) or other atoms. So we can eliminate the option with \( S \) (the first option).

Step2: Analyze the number of oxygen atoms

\( CO_2 \) has two oxygen atoms, so we can eliminate the option with only one \( O \) atom (the third option).

Step3: Analyze the electron dots around oxygen atoms

Each oxygen atom in \( CO_2 \) should have 4 non - bonding electrons (2 lone pairs) to satisfy the octet rule. Let's check the remaining options:

• For the second option (\( \dot{O}=C = \dot{O} \) with proper electron dots), each \( O \) has 2 lone pairs (4 non - bonding electrons), and the central \( C \) is double - bonded to two \( O \) atoms, which is the correct Lewis structure for \( CO_2 \).
• For the fourth option, the number of non - bonding electrons around the right \( O \) is incorrect (it has 3 non - bonding electrons instead of 4).

Answer:

The second option (the one with \( O = C = O \) and proper electron dots around each \( O \))