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

• A. Organic acids such as CH_3COOH (acetic acid) in pure form
• B. Covalent compounds such as C_6H_{12}O_6 (glucose)
• C. Nonpolar molecules such as O_2
• 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 into their constituent ions (Na\^+ and Cl\^- ) when dissolved in water, producing free ions that conduct electricity.
3. Note that organic acids such as CH\_3COOH (acetic acid) are weak electrolytes; they partially ionize in water, so they conduct electricity but not as well as strong electrolytes.
4. Identify that covalent compounds like C\_6H\_{12}O\_6 (glucose) do not ionize in water; they dissolve as neutral molecules and therefore do not conduct electricity.
5. Understand that nonpolar molecules such as O\_2 do not ionize or produce ions in water, so they do not conduct electricity.