Final answer:
The correct dissociation equation for calcium chloride in water is CaCl₂ (s) → Ca²⁺ (aq) + 2 Cl⁻ (aq), detailing the separation into a 2+ charged calcium ion and two 1- charged chloride ions.
Step-by-step explanation:
The equation that best describes calcium chloride (CaCl₂) when it dissociates in water is CaCl₂ (s) → Ca²⁺ (aq) + 2 Cl⁻ (aq). When calcium chloride dissolves, it separates into one calcium ion with a 2+ charge and two chloride ions, each with a 1- charge. This dissociation is important for understanding how ionic compounds like calcium chloride behave in aqueous solutions and relates to properties such as freezing point depression and boiling point elevation.
For every formula unit of CaCl₂ that dissolves in water, there are three ions produced, therefore the colligative properties, such as freezing point depression and boiling point elevation, would increase threefold compared to an equal concentration of a nonelectrolyte. This example parallels the behavior of other salts in solution and highlights the concept of electrical neutrality where the charges of the dissociated ions must balance overall.