Draw the best Lewis structure for NCCH2C(O)CH2CHO, a neutral molecule.
Show all atoms, bonds, lone pairs, and formal charges.
To draw the Lewis structure for NCCH2C(O)CH2CHO, we need to follow these steps:
Step 1: Calculate the total number of valence electrons.
To do this, we count the valence electrons of each atom and add them up.
N: 5
C: 4 (x 3)
H: 1 (x 6)
O: 6 (x 2)
Total valence electrons: 5 + (4 x 3) + (1 x 6) + (6 x 2) = 33
Step 2: Determine the central atom.
The central atom is usually the least electronegative atom that is capable of forming multiple bonds. In this case, nitrogen (N) is the central atom.
Step 3: Connect the atoms using single bonds.
Connect the atoms with single bonds, starting from the central atom (nitrogen) and extending to the surrounding atoms. Hydrogen atoms (H) can only form single bonds, while carbon (C) and oxygen (O) atoms can form multiple bonds.
Step 4: Distribute the remaining electrons.
After connecting the atoms with single bonds, distribute the remaining electrons in pairs around the atoms, satisfying the octet rule (except for hydrogen, which only needs 2 electrons). Start by filling the octets of the terminal atoms (C, O, H), and distribute the remaining electrons to the central atom (N).
Step 5: Check for octet rule fulfillment.
After distributing the electrons, check if all atoms (except hydrogen) have achieved an octet (8 electrons) or a duet (2 electrons). If any atoms have incomplete octets, move electron pairs from surrounding atoms to form double or triple bonds until all atoms satisfy the octet rule.
Step 6: Assign formal charges.
Check if any atoms have formal charges (when the number of valence electrons differs from the assigned electrons). Adjust the position of lone pairs as needed to minimize formal charges. Negative formal charges should be placed on more electronegative atoms, while positive formal charges should be placed on less electronegative atoms.
Following these steps, the Lewis structure for NCCH2C(O)CH2CHO is drawn as follows:
H H
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H - C - C - N - C - O
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H O
In this structure, carbon forms a double bond with the nitrogen, as indicated by the double lines, and another double bond with the oxygen. The nitrogen and oxygen atoms have lone pairs of electrons. The hydrogen atoms are bonded to their respective carbon atoms.
Please note that the formal charges might need to be calculated explicitly based on the structure and the electronegativity of the atoms involved.