Final answer:
The compound Na₂CO₃ is composed of Na⁺ and CO₃²− ions. Sodium carbonate dissociates into these ions when dissolved in water. The correct answer to the question is option b, which lists Na⁺ ions and CO₃²− ions.
Step-by-step explanation:
The solid compound Na₂CO₃, or sodium carbonate, is composed of Na+ ions and CO₃²− ions. When sodium carbonate is dissolved in water, it separates into two sodium cations, Na⁺, and one carbonate anion, CO₃²−. The carbonate ion is a polyatomic ion with a charge of 2-, which means that each sodium ion balances out half of the carbonate's charge since each sodium ion has a charge of 1+.
In the chemical reaction CO₂ (aq) + 2NaOH(aq) → Na₂CO3(aq) + H₂O(l), sodium hydroxide (NaOH) reacts with carbon dioxide (CO₂) to form sodium carbonate (Na₂CO3) and water (H₂O). Here, Na⁺ and CO₃²− are the resultant ions from the dissociation of sodium carbonate in the aqueous solution. Ionic compounds, such as NaOH and Na₂CO3, dissociate fully to yield ions in water.
The question's correct answer is option b: Na⁺ ions and CO₃²− ions, representing the presence of sodium ions and carbonate ions in sodium carbonate.