molekulmassit

Molekulmassit, often referred to as molecular weight, is a fundamental property of chemical substances. It represents the sum of the atomic masses of all atoms in a molecule, expressed in atomic mass units (amu). To determine the molecular mass of a compound, one must first identify its chemical formula and then consult a periodic table for the atomic mass of each element present. These atomic masses are then multiplied by the number of atoms of that element in the molecule and summed together. For example, the molecular mass of water (H₂O) is calculated by taking twice the atomic mass of hydrogen (approximately 1.01 amu each) and adding the atomic mass of oxygen (approximately 16.00 amu), resulting in approximately 18.02 amu. Molecular mass is crucial in various chemical calculations, including stoichiometry, where it is used to convert between mass and moles of a substance. It also plays a role in determining physical properties like boiling point and vapor pressure. While often used interchangeably with molar mass, molecular mass refers specifically to a single molecule, whereas molar mass refers to the mass of one mole of that substance, which is numerically equivalent but has units of grams per mole (g/mol).