Kelarutan dan Hasil Kali Kelarutan (Ksp) Kimia Kelas 11 • Part 2: Soal Hubungan Kelarutan dan Ksp

Introduction

This tutorial provides a step-by-step guide on solubility and the solubility product constant (Ksp), as discussed in the second part of the video series on this topic. The video covers practical examples and calculations relevant to high school chemistry students. Understanding these concepts is essential for mastering the relationships between solubility and Ksp.

Step 1: Determine Solubility and Ksp from Mass Data

• Identify the substance: Start with the given mass of the solute that dissolves in a specific volume of solvent.
• Calculate molarity:
  • Determine the molar mass of the solute.
  • Use the formula: [ \text{Molarity (M)} = \frac{\text{moles of solute}}{\text{volume of solution in liters}} ]
• Calculate Ksp:
  • Write the dissociation equation for the solute.
  • Use the molarity values of the ions produced to find Ksp using: [ Ksp = [\text{Ion}_1]^{\text{coefficient}} \times [\text{Ion}_2]^{\text{coefficient}} ]

Step 2: Determine pH and Mass of Base from Ksp

• Given Ksp: Use the known Ksp value for the base.
• Calculate molarity of the base:
  • Write the dissociation reaction.
  • Use the Ksp expression to find the molarity of the base.
• Calculate pH:
  • Convert the molarity of the base into pOH: [ \text{pOH} = -\log[\text{Base}] ]
  • Use the relationship between pH and pOH: [ \text{pH} + \text{pOH} = 14 ]

Step 3: Calculate Ksp from pH of Saturated Solution

• Given pH: Start with the pH of the saturated solution.
• Calculate pOH: [ \text{pOH} = 14 - \text{pH} ]
• Determine hydroxide ion concentration: [ [\text{OH}^-] = 10^{-\text{pOH}} ]
• Use stoichiometry: Relate the concentration of ions to the Ksp expression as done in Step 1.

Step 4: Compare Solubility from Known Ksp Values

• List Ksp values: Collect Ksp values for the compounds you want to compare.
• Convert Ksp to molarity:
  • For each Ksp, solve for the molarity of the compound.
• Rank solubility: Arrange the compounds from highest to lowest solubility based on their calculated molarity.

Conclusion

In this guide, we have walked through the essential calculations and concepts related to solubility and Ksp. By mastering these steps, students will enhance their understanding of how solubility and Ksp interact in chemical reactions. For further learning, consider reviewing the previous video in the series to solidify your grasp of these foundational concepts.