Which of the following substances conducts electricity when dissolved in water?

• A. C_6H_{12}O_6 (glucose)
• B. NaCl
• C. CCl_4
• D. CH_3OH (methanol)

Answer: (B)

Verified step by step guidance

1. Understand that electrical conductivity in aqueous solutions depends on the presence of ions that can move freely and carry charge.
2. Recognize that substances like NaCl are ionic compounds that dissociate into Na\textsuperscript{+} and Cl\textsuperscript{-} ions when dissolved in water, allowing the solution to conduct electricity.
3. Note that glucose (C_6H_{12}O_6) and methanol (CH_3OH) are molecular compounds that dissolve as intact molecules without producing ions, so their solutions do not conduct electricity.
4. Identify that CCl_4 is a nonpolar molecular compound that does not dissolve well in water and does not produce ions, so it does not conduct electricity.
5. Conclude that among the given substances, only NaCl conducts electricity in aqueous solution due to its ionic dissociation.