Reaksjonsligninger

Reaksjonsligninger, or chemical equations, are symbolic representations of chemical reactions. They show the substances that react with each other (reactants) and the substances that are formed as a result of the reaction (products). The general form of a chemical equation is reactants → products. A chemical equation provides essential information about a chemical transformation, including the identities of the substances involved and their relative amounts.

Atoms are rearranged during a chemical reaction, but they are neither created nor destroyed. This principle is known as the law of conservation of mass, and it is fundamental to writing correct chemical equations. Therefore, chemical equations must be balanced. Balancing an equation involves adjusting the stoichiometric coefficients (the numbers placed in front of the chemical formulas) so that the number of atoms of each element is the same on both the reactant and product sides. For example, the formation of water from hydrogen and oxygen is represented by the unbalanced equation H₂ + O₂ → H₂O. To balance it, we write 2H₂ + O₂ → 2H₂O, ensuring four hydrogen atoms and two oxygen atoms on each side.

Chemical equations can also include state symbols in parentheses to indicate the physical state of each substance: (s) for solid, (l) for liquid, (g) for gas, and (aq) for aqueous solution. For instance, the combustion of methane is written as CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g). Reaksjonsligninger are a crucial tool in chemistry for understanding, predicting, and quantifying chemical processes.