Indicate the concentration of each ion present in the solution formed by mixing: (c) 3.60 g KCl in 75.0 mL of 0.250 M CaCl₂ solution. Assume that the volumes are additive.

Verified step by step guidance

1. Calculate the moles of KCl: Use the molar mass of KCl to convert grams to moles.
2. Determine the concentration of KCl: Divide the moles of KCl by the total volume of the solution in liters.
3. Calculate the moles of CaCl_2: Use the given molarity and volume to find the moles of CaCl_2.
4. Determine the concentration of CaCl_2: Since the volume is additive, divide the moles of CaCl_2 by the total volume of the solution in liters.
5. Identify the ions present: KCl dissociates into K^+ and Cl^- ions, and CaCl_2 dissociates into Ca^{2+} and Cl^- ions. Calculate the concentration of each ion based on their stoichiometry in the compounds.

Key Concepts

Molarity

Molarity (M) is a measure of concentration defined as the number of moles of solute per liter of solution. It is crucial for calculating the concentration of ions in a solution, especially when mixing different solutions. In this question, the molarity of the CaCl2 solution is given, which helps determine the concentration of calcium and chloride ions after mixing.

Dissociation of Ionic Compounds

Ionic compounds, such as KCl and CaCl2, dissociate into their constituent ions when dissolved in water. For example, KCl dissociates into K+ and Cl- ions, while CaCl2 dissociates into Ca2+ and 2Cl- ions. Understanding this dissociation is essential for calculating the total concentration of ions in the mixed solution.

Mass-to-Moles Conversion

To find the concentration of ions from a given mass of solute, it is necessary to convert grams to moles using the molar mass of the compound. For KCl, the molar mass is approximately 74.55 g/mol. This conversion allows for the determination of the number of moles of KCl present in the solution, which is then used to find the concentration of K+ and Cl- ions.