Which of the following best represents the correct Lewis structure for $C_2{H}_{2}O$ (glyoxal)?

• A. Two carbon atoms connected by a single bond, each carbon bonded to one hydrogen, and each carbon double bonded to an oxygen atom
• B. Two carbon atoms connected by a double bond, each carbon bonded to one hydrogen, and one carbon double bonded to an oxygen atom while the other carbon is single bonded to an oxygen atom
• C. Two carbon atoms connected by a double bond, each carbon bonded to one hydrogen, and one carbon double bonded to an oxygen atom
• D. Two carbon atoms connected by a triple bond, each carbon bonded to one hydrogen, and one carbon single bonded to an oxygen atom

Answer: (B)

Verified step by step guidance

1. Step 1: Determine the molecular formula and the total number of valence electrons. Glyoxal has the formula C\_2H\_2O\_2. Carbon has 4 valence electrons, hydrogen has 1, and oxygen has 6. Calculate the total valence electrons by summing these contributions.
2. Step 2: Consider the connectivity of atoms. Glyoxal is known as an aldehyde derivative with two carbonyl groups. Each carbon is bonded to one hydrogen and one oxygen atom, and the two carbons are connected to each other. This suggests each carbon is bonded to one hydrogen and double bonded to an oxygen atom.
3. Step 3: Draw a skeletal structure with two carbon atoms connected by a single bond. Attach one hydrogen to each carbon and double bond each carbon to an oxygen atom. This arrangement satisfies the valence requirements for carbon (4 bonds), oxygen (2 bonds), and hydrogen (1 bond).
4. Step 4: Verify the octet rule for each atom. Each carbon should have 8 electrons around it (counting bonds), each oxygen should have 8 electrons (including lone pairs), and each hydrogen should have 2 electrons. Adjust bonds if necessary to satisfy these rules.
5. Step 5: Compare the drawn structure with the given options. The correct Lewis structure for glyoxal is two carbon atoms connected by a single bond, each carbon bonded to one hydrogen, and each carbon double bonded to an oxygen atom.