Which of the following substances will most likely dissociate into ions when dissolved in water?

• A. NaCl
• B. C_6H_{12}O_6
• C. CO_2
• D. CH_3OH

Answer: (A)

Verified step by step guidance

1. Understand that substances that dissociate into ions in water are typically ionic compounds, which consist of positive and negative ions held together by ionic bonds.
2. Recognize that NaCl (sodium chloride) is an ionic compound composed of Na⁺ and Cl⁻ ions, so it will dissociate into these ions when dissolved in water.
3. Identify that C_6H_{12}O_6 (glucose), CO_2 (carbon dioxide), and CH_3OH (methanol) are molecular compounds, which generally do not dissociate into ions but rather dissolve as intact molecules.
4. Recall that molecular compounds may dissolve in water due to hydrogen bonding or dipole interactions but do not produce ions that conduct electricity like ionic compounds do.
5. Conclude that among the given substances, NaCl is the one that will most likely dissociate into ions when dissolved in water.