Molecular Weight (MW)

In chemistry, molecular weight (MW), also known as molecular mass or relative molecular mass, is a fundamental property of a molecule. It represents the mass of one mole of that molecule – that is, the total mass of all the atoms that comprise it. Molecular weight is calculated by summing the atomic weights of each unique atom present in the molecule. The atomic weight of each element is based on the carbon-12 isotope, which is defined as the standard against which all other atomic weights are measured. The unit most commonly used for expressing molecular weight is the dalton (Da), which is equivalent to one atomic mass unit (amu). Therefore, understanding molecular weight is crucial for stoichiometric calculations and many other aspects of chemical reactions and analyses.