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Hydrolysis of Salts

pH Chart In our last post: Types, Preparation & Uses of Salts , we studied that salts are the products of the neutralization reactions between acids and bases. Following this fact, all salts are expected to have a neutral pH of 7 in solution. Interestingly, some salts produce solutions with pH > 7 (basic solutions), while others produce acidic solutions with pH < 7. Such salts, which are the products of either weak acids and strong bases or strong acids and weak bases, decompose in water to form two products. This phenomenon is known as hydrolysis. Recall that from our post on pH in Acids & Bases (Part III) , we learnt that water contains equal concentration of hydrogen and hydroxide ions. Therefore, the dissolution of a salt in water is likely to upset this ionic equilibrium based on the salt's composition. This is the underlying principle of hydrolysis of salts. So, in this post, we shall be looking at the hydrolysis of different types of salts based on th...

Salts: Types, Preparation & Uses

Introduction Before they are introduced to acids and bases, young chemistry students always think that sodium chloride (common salt) is everything there is to know about salts. However, from their knowledge of acids and bases, they also get to know about other substances, such as copper (II) tetraoxosulphate (VI), potassium trioxocarbonate (IV), ammonium chloride, calcium trioxonitrate (V) etc, which are classified as salts. These substances are the outcomes of the Arrhenius acid-base reactions. So, what is a salt? Definitions We will define a salt in terms of basicity (replaceable hydrogen ions) and neutralization. I) A salt is a substance formed when all or part of the replaceable hydrogen ions in an acid, are replaced by metallic ions (Na+, K+, Mg2+, Ca2+, Cu2+ etc) or ammonium ions (NH4+). This implies that every acid has its corresponding salts. The list below shows examples of some salts and their parent acids. 1. Acid : Hydrochloric acid (HCl) Salts : Sodium chloride...