Final answer:
The correct expression for the ions present in a solution of K₂CO₃ is K⁺(aq), K⁺(aq), CO₃²⁻(aq).
Step-by-step explanation:
In a solution of K₂CO₃ (potassium carbonate), the ions present are two potassium ions (K⁺) and one carbonate ion (CO₃²⁻). When potassium carbonate dissolves in water, the ionic compound separates into its constituent ions. Each unit formula of potassium carbonate yields two potassium ions and one carbonate ion as a result of dissociation.
The ions present in a solution of K₂CO₃ are K⁺(aq), K⁺(aq), and CO₃²⁻(aq). The student correctly identified the potassium and carbonate ions but did not account for there being two potassium ions for every carbonate ion.
It's essential to note that in cases where more than one polyatomic ion is needed to balance the overall charge in the formula, parentheses should be used. However, for the dissociation of K₂CO₃, this is not necessary since there is only one carbonate ion