Write Lewis structures that obey the octet rule (duet rule for H) for each of the following molecules. a. \(\mathrm{H}_{2} \mathrm{CO}\) b. \(\mathrm{CO}_{2}\) c. \(\mathrm{HCN}\) Carbon is the central atom in all of these molecules.

Determine the number of valence electrons for each atom in the molecule, using the following periodic groups: Group 1 elements: 1 valence electron Group 2 elements: 2 valence electrons Group 13 elements: 3 valence electrons Group 14 elements: 4 valence electrons Group 15 elements: 5 valence electrons Group 16 elements: 6 valence electrons Group 17 elements: 7 valence electrons

Before distributing the remaining electrons, it's important to connect each of the atoms with single bonds.

Finally, distribute the remaining electrons among the atoms so that they follow the octet rule (or duet rule for Hydrogen). a. \(\mathrm{H}_{2}\mathrm{CO}\): Step 1: Calculate Valence Electrons for Each Atom - \(\mathrm{H}\) has 1 valence electron (x2 since there are 2 hydrogens) - \(\mathrm{C}\) has 4 valence electrons - \(\mathrm{O}\) has 6 valence electrons Total valence electrons: 1(2) + 4 + 6 = 12 Step 2: Connect Atoms with Single Bonds Connect the carbon atom with each of the hydrogen atoms and the oxygen atom using single bonds. Step 3: Distribute the Remaining Electrons After forming the single bonds, we are left with 12 - 2(2) - 2 = 6 electrons. We distribute these electrons onto the oxygen atom to satisfy its octet rule. The Lewis structure for \(\mathrm{H}_{2}\mathrm{CO}\) is: H - C = O b. \(\mathrm{CO}_{2}\): Step 1: Calculate Valence Electrons for Each Atom - \(\mathrm{C}\) has 4 valence electrons - \(\mathrm{O}\) has 6 valence electrons (x2 since there are 2 oxygens) Total valence electrons: 4 + 6(2) = 16 Step 2: Connect Atoms with Single Bonds Connect the carbon atom with each of the oxygen atoms using single bonds. Step 3: Distribute the Remaining Electrons After forming the single bonds, we are left with 16 - 2(2) = 12 electrons. We distribute these electrons by forming double bonds between carbon and each of the oxygen atoms. The Lewis structure for \(\mathrm{CO}_{2}\) is: O = C = O c. \(\mathrm{HCN}\): Step 1: Calculate Valence Electrons for Each Atom - \(\mathrm{H}\) has 1 valence electron - \(\mathrm{C}\) has 4 valence electrons - \(\mathrm{N}\) has 5 valence electrons Total valence electrons: 1 + 4 + 5 = 10 Step 2: Connect Atoms with Single Bonds Connect the hydrogen atom with the carbon atom and the carbon atom with the nitrogen atom using single bonds. Step 3: Distribute the Remaining Electrons After forming the single bonds, we are left with 10 - 2(2) = 6 electrons. We distribute these electrons by forming a triple bond between carbon and nitrogen. The Lewis structure for \(\mathrm{HCN}\) is: H - C ≡ N