centimole

Centimole is a unit of amount of substance equal to 0.01 mole. It is obtained by applying the centi- prefix to the mole, the SI base unit for amount of substance. While not a separate SI base unit, the centimole is used in contexts where expressing small quantities in steps of 0.01 mole is convenient.

In some fields, especially soil science and agronomy, centimoles of charge per kilogram are used to describe the concentration of exchangeable ions. This notation uses cmolc/kg, where the “c” denotes charge. In such cases, 1 cmolc/kg corresponds to 0.01 moles of electrical charge per kilogram of soil. The plain unit cmol (without the charge designation) is also used to express small molar amounts, with 1 cmol equal to 0.01 mole.

Examples and common usage: 1 cmol = 0.01 mol. A measurement of 50 cmolc/kg indicates 0.50 mol of charge per kilogram of soil. Centimoles of charge per kilogram are frequently appearing in soil tests reporting cation exchange capacity (CEC) and related nutrient measurements, where the focus is on the quantity of charge carried by ions rather than the number of ions alone.