Which of the following best explains why certain substances conduct electricity when dissolved in water?

• A. They form covalent bonds with water molecules, allowing electrons to flow.
• B. They dissociate into ions that are free to move and carry electric charge.
• C. They react with water to produce neutral molecules that conduct electricity.
• D. They increase the temperature of the solution, which enhances conductivity.

Answer: (B)

Verified step by step guidance

1. Understand that electrical conductivity in aqueous solutions depends on the presence of charged particles that can move freely.
2. Recognize that substances which conduct electricity when dissolved in water typically do so because they break apart into ions, which are charged species.
3. Recall that ionic compounds dissociate into positive and negative ions in water, allowing these ions to move and carry electric current.
4. Note that covalent compounds generally do not dissociate into ions in water, so they do not conduct electricity unless they ionize.
5. Conclude that the best explanation is that substances conduct electricity because they dissociate into ions that are free to move and carry electric charge.