Question

what is the molarity of potassium ions in a 0.122 m k₂cro₄ solution?

Explanation:

Step1: Identify starting molarity

Starting amount: $0.122\ \text{M } K_2CrO_4$

Step2: Use ion mole ratio

From $K_2CrO_4$, ratio: $\frac{2\ \text{mol } K^+}{1\ \text{mol } K_2CrO_4}$

Step3: Calculate $K^+$ molarity

$0.122\ \text{M } K_2CrO_4 \times \frac{2\ \text{mol } K^+}{1\ \text{mol } K_2CrO_4}$

Answer:

$0.244\ \text{M } K^+$