what is the molarity of Br^- in each solution? a. 0.100 M KBr

Verified step by step guidance

1. Step 1: Understand the problem. We need to find the molarity of \( \text{Br}^- \) ions in a solution of \( 0.100 \text{ M} \) \( \text{KBr} \).
2. Step 2: Recognize that \( \text{KBr} \) is a strong electrolyte and dissociates completely in water into \( \text{K}^+ \) and \( \text{Br}^- \) ions.
3. Step 3: Write the dissociation equation: \( \text{KBr} \rightarrow \text{K}^+ + \text{Br}^- \).
4. Step 4: Note that the stoichiometry of the dissociation is 1:1, meaning each mole of \( \text{KBr} \) produces one mole of \( \text{Br}^- \).
5. Step 5: Conclude that the molarity of \( \text{Br}^- \) ions is the same as the initial molarity of \( \text{KBr} \), which is \( 0.100 \text{ M} \).

Key Concepts

Molarity

Molarity is a measure of concentration defined as the number of moles of solute per liter of solution. It is expressed in units of moles per liter (M). Understanding molarity is essential for calculating the concentration of ions in a solution, as it allows for the conversion between moles of solute and the volume of the solution.

Dissociation of Ionic Compounds

Ionic compounds, such as potassium bromide (KBr), dissociate into their constituent ions when dissolved in water. For KBr, it separates into K⁺ and Br^- ions. This dissociation is crucial for determining the concentration of specific ions in solution, as the molarity of the compound directly translates to the molarity of its ions.

Stoichiometry in Solutions

Stoichiometry involves the quantitative relationship between reactants and products in a chemical reaction. In the context of solutions, it helps in calculating the amounts of ions produced from a given concentration of an ionic compound. For example, knowing that 1 mole of KBr produces 1 mole of Br^- allows us to directly relate the molarity of KBr to the molarity of Br^- in solution.