Laboratory work

Hydrolysis of salts

Purpose of the work: To understand the regularity of hydrolysis reaction and to determine the solubility medium. To master molecular equations of salt hydrolysis and to show the solution solution.

Materials:

· Aluminium chloride AlCl₃

· Potassium carbonate K₂CO₃

· Ammonium chloride NH₄Cl

· Sodium hydrogen carbonate NaHCO₃

· Sodium phosphate Na₃PO₄

· Disodium hydrogen phosphate Na₂HPO₄

· Sodium dihydrogen phosphate NaH₂PO₄

· Beaker

· Distilled water

· Methylorande

· Mixing spoon

Procedure:

1. All glasses should be distilled with water.

2. Add methylenorange to water and stir

3. Apply a drop of a solution of aluminium chloride AlCl₃, potassium carbonate K₂CO₃, ammonium chloride NH₄Cl, sodium hydrogen carbonate NaHCO₃, Sodium phosphate Na₃PO₄, disodium hydrogen phosphate Na₂HPO₄ and sodium dihydrogen phosphate NaH₂PO₄.

4. By changing the color of the solution, it is inferred that the reaction of the medium in the solution of each salt takes place.

5. Add condensed, ionic and molecular equilibrium reactions to hydrolysis, such as pH. At a step of hydrolysis, the reaction of the reaction is only for the first stage.

6. Make a conclusions that some types of hydrolysis are exposed.

Questions:

1. What chemical process is called hydrolysis? What is the essence of hydrolysis?

2. What is the pH of the solution? How does it estimate it? Give an example.

3. Which salts are hydrolyzed? What are the salts free of hydrolysis? Why? Give an example and comment.

4. Which of the following salts of KCN, K₃PO₄, CrCl₃, NaBr, KNO₃, Al₂ (SO₄)₃ is hydrolyzed? Write the hydrolysis equations. Define the reaction of the medium.

5. What is the hydrolysis constant? What does it describe? What factors depend?

6. What is the degree of hydrolysis? What factors are involved?