Which of the following types of molecules conduct electricity when dissolved in water?

• A. Organic acids such as CH3COOH (acetic acid)
• B. Covalent compounds such as C6H12O6 (glucose)
• C. Nonpolar molecules such as O2
• D. Ionic compounds such as NaCl

Answer: (D)

Verified step by step guidance

1. Understand that electrical conductivity in aqueous solutions depends on the presence of charged particles called ions that can move freely and carry electric current.
2. Recognize that ionic compounds like NaCl dissociate completely into their constituent ions (Na\^{+} and Cl\^{-}) when dissolved in water, allowing the solution to conduct electricity.
3. Note that organic acids such as CH3COOH are weak electrolytes; they partially ionize in water, producing some ions but not as many as ionic compounds, so they conduct electricity weakly.
4. Identify that covalent compounds like C6H12O6 (glucose) do not ionize in water; they dissolve as neutral molecules and therefore do not conduct electricity.
5. Understand that nonpolar molecules such as O2 do not dissolve well in water and do not produce ions, so they do not conduct electricity when dissolved.