Which of the following is the correct conjugate base of the acid ${\left(CH3\right)}_{2}C=OH+$?

• A. ${\left(CH3\right)}_{2}C=O-$
• B. ${\left(CH3\right)}_{2}C=O$
• C. ${\left(CH3\right)}_{2}C=OH$
• D. ${\left(CH3\right)}_{2}C-OH$

Answer: (B)

Verified step by step guidance

1. Identify the acid given: it is acetic acid, represented as \(\left(\mathrm{CH}_3\right)_2\mathrm{C}=\mathrm{OH}^+\), which is a protonated form of a carbonyl compound (likely a protonated ketone or similar).
2. Recall that the conjugate base of an acid is formed by the loss of a proton (H\(^+\)) from the acid. This means you remove one hydrogen ion from the acidic site.
3. Determine the acidic proton in the molecule. In this case, the acidic proton is the hydrogen attached to the oxygen atom (the hydroxyl group).
4. Remove the proton (H\(^+\)) from the hydroxyl group to form the conjugate base. This results in the oxygen bearing a negative charge, changing \(\mathrm{OH}\) to \(\mathrm{O}^-\).
5. Write the conjugate base structure as \(\left(\mathrm{CH}_3\right)_2\mathrm{C}=\mathrm{O}^-\), indicating the loss of the proton and the negative charge on the oxygen.