Chemistry – Acids, bases and salts - Preparation of salts | e-Consult
Acids, bases and salts - Preparation of salts (1 questions)
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The solubility of salts is governed by several general rules. These rules are based on the ionic charges and the lattice energy of the crystal structure. Here's a breakdown of the solubility of the specified salt types:
- Sodium, Potassium and Ammonium Salts: Salts of sodium (Na+), potassium (K+) and ammonium (NH4+) are generally soluble in water. This is because these ions have relatively low charge densities and the hydration energy of the ions is high, overcoming the lattice energy.
- Nitrates: All nitrates (NO3-) are soluble in water. The nitrate ion is a strong, weakly coordinating anion, leading to high solubility.
- Chlorides: Most chlorides (Cl-) are soluble in water. However, there are exceptions. Specifically, chlorides of silver (AgCl), lead (PbCl2) and mercury(I) (Hg2Cl2) are insoluble.
- Sulfates: Most sulfates (SO42-) are soluble in water. However, sulfates of barium (BaSO4), calcium (CaSO4), and lead (PbSO4) are insoluble. This is due to the high ionic charges of Ba2+, Ca2+ and Pb2+, which result in a high lattice energy.
- Carbonates: Most carbonates (CO32-) are insoluble in water. The exception are carbonates of sodium (Na2CO3), potassium (K2CO3) and ammonium (NH4)2CO3. These are soluble because the alkali metal cations and ammonium ion have high charge densities, which increases the hydration energy and overcomes the lattice energy.
- Hydroxides: Most hydroxides (OH-) are insoluble in water. The exceptions are hydroxides of sodium (NaOH), potassium (KOH), ammonium (NH4OH) and calcium (Ca(OH)2), which are only partially soluble. The solubility of calcium hydroxide is limited, but it does dissolve to a small extent.