\textbf{233 –} The sum of the oxidation numbers of carbon atoms in a molecule of benzoic acid equals the oxidation number of which element in the given compound?
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(1) S in potassium sulfide \hspace{1cm} (2) C in formaldehyde \\
(3) N in nitric acid \hspace{1cm} (4) Cl in potassium chlorate
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