Molekularform

Molekularform, also known as molecular formula, is a notation used in chemistry to represent the exact number of atoms of each element present in a molecule of a chemical compound. It provides unambiguous information about the composition of a molecule. For example, the molecular formula for water is H2O, indicating that each molecule of water contains two hydrogen atoms and one oxygen atom. Similarly, the molecular formula for glucose is C6H12O6, showing six carbon atoms, twelve hydrogen atoms, and six oxygen atoms.

The molecular formula is derived from the empirical formula, which represents the simplest whole-number ratio of atoms in a compound. To determine the molecular formula from the empirical formula, the molar mass of the compound must also be known. The molecular formula is always a whole-number multiple of the empirical formula. For instance, if the empirical formula of a compound is CH2O and its molar mass is 180.16 g/mol, and the molar mass of CH2O is 30.03 g/mol, then the molecular formula is (CH2O)n, where n = 180.16 / 30.03 ≈ 6. Thus, the molecular formula is C6H12O6.

Molecular formulas are crucial for understanding the structure and properties of chemical substances. They are fundamental in stoichiometry, chemical reactions, and the identification of unknown compounds. Different compounds can have the same empirical formula but different molecular formulas, leading to isomers which are molecules with the same chemical formula but different structural arrangements of atoms.