molbråk

Molbrøk, also known as mole fraction, is a dimensionless quantity used in chemistry to express the composition of a mixture. It is defined as the ratio of the number of moles of a particular component to the total number of moles of all components in the mixture. Mathematically, the mole fraction of component i, denoted as x_i, is calculated as: x_i = n_i / n_total, where n_i is the number of moles of component i and n_total is the sum of moles of all components in the mixture.

The sum of mole fractions of all components in a mixture is always equal to 1. For example, in a binary mixture containing components A and B, x_A + x_B = 1. Mole fractions are useful because they are independent of temperature and pressure, making them a convenient way to describe the composition of solutions and gas mixtures. They are commonly used in thermodynamics, physical chemistry, and chemical engineering. Unlike mass percentage or volume percentage, mole fraction directly relates to the number of particles present, which is often crucial for understanding reaction stoichiometry and colligative properties. It is a fundamental concept for describing ideal and non-ideal solutions.