In the context of complete ionic equations, which of the following best describes spectator ions?

• A. Ions that do not participate in the chemical reaction and remain unchanged in solution.
• B. Ions that are involved in the formation of a gas or water.
• C. Ions that form a precipitate during the reaction.
• D. Ions that are produced only as a result of the reaction.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand what a complete ionic equation represents. It shows all the ions present in a solution, including those that participate in the reaction and those that do not.
2. Step 2: Identify the ions that undergo a chemical change during the reaction, such as forming a precipitate, gas, or water. These ions are called 'reactive ions' or 'participating ions.'
3. Step 3: Recognize that spectator ions are ions present in the solution that do not change their oxidation state or form new compounds; they remain dissolved and unchanged on both sides of the equation.
4. Step 4: Compare the options given: ions involved in gas or water formation, ions forming precipitates, and ions produced only as a result of the reaction are all participating ions, not spectators.
5. Step 5: Conclude that spectator ions are best described as ions that do not participate in the chemical reaction and remain unchanged in solution.