Salts

In chemistry, a salt is an ionic compound composed of positively charged cations and negatively charged anions. Most salts form when an acid reacts with a base in a neutralization reaction, producing a salt and water. Salts can also form by other routes, such as reactions between acids and metal carbonates or between strong acids and metal oxides. The term covers a broad range of compounds, from simple salts consisting of a metal ion paired with a nonmetal or polyatomic ion to organic salts.

Salts are typically crystalline solids with high melting points. They dissolve in water by dissociating into ions, and their solubility varies widely depending on lattice energy and hydration energy. Some salts are highly soluble, while others are sparingly soluble. Solutions of salts derived from strong acids and strong bases are usually neutral, whereas salts of weak acids or bases can be slightly acidic or basic due to hydrolysis.

Many salts occur naturally as minerals and in seawater. Halite, or rock salt, is the common source of sodium chloride used for seasoning and preservation. Salts have extensive applications in industry and daily life, including chemical manufacturing, de-icing roads, water treatment, and agriculture. Organic salts, such as ammonium salts, also play important roles in chemistry and various industrial processes.

The term salt historically referred especially to sodium chloride, reflecting longstanding usage. In modern chemistry, the concept encompasses a wide class of ionic compounds formed from the cation of a base and the anion of an acid, encompassing both inorganic and organic examples.