Final answer:
The formal charge on oxygen in dimethyl ether, CH3OCH3, is 0 because oxygen is bonded to two carbon atoms and has two lone pairs. It has 6 valence electrons, 4 non-bonding electrons, and 2 bonding electrons, which results in a formal charge of 0.
Step-by-step explanation:
The formal charge on an atom in a molecule can be calculated using the formula: Formal charge = (valence electrons) - (non-bonding electrons) - (1/2 bonding electrons). In dimethyl ether, CH3OCH3, the oxygen atom is bonded to two carbon atoms and has four non-bonding electrons (two lone pairs). Oxygen has 6 valence electrons normally. The bonding situation around oxygen in CH3OCH3 involves two single bonds, accounting for 2 bonding electrons. Applying the formula: Formal charge = 6 - 4 - (1/2 × 4) = 6 - 4 - 2 = 0. Therefore, the formal charge on oxygen in dimethyl ether is 0.