What is a solution concentration?

solutions are homogeneous mixtures that result from dissolution, at the molecular level, one or more "soluts" in the "solvent" - dissolved medium. The solvent may also consist of more than one substance if it is also dissolved. In normal use, the word solution applies to substances dissolved in liquid solvent, although the wide use of the word is not so limited. Scientists call the amount of solut or wealth within the solution of the solution concentration. There are a number of ways to quantify - or assign a numeric value concentration. Especially among analytical chemists is the most common unit for reporting the concentration of the solution of "molarity". This term is derived from the word "mole", referring to the molecular weight of a particular compound in grams. The closer can easily see that because their molecular weight differs, the mole sugar is not the same as the mole of salt.

Consider how to admitRavy one molar table salt solution. Sodium chloride has a chemical formula NaCl - it is a reaction product produced by a combination of sodium metal (on) with chlorine gas (CL). Sodium atomic weight is 22.99; Atomic weight of chlorine is 35.45. A simple addition gives the molecular weight of the salt as 58.44 - ie the NaCl MOL weighs 58.44 grams. The dissolution of this amount of NaCl in water to create a liter (1.06 liters) of the solution leads to exactly one molar solution (1.0 m).

Less frequently, the concentration of solution can be expressed in terms of "normality" or "molality". Definition of normality is not much different from the definition for molarity, but includes the concept of “equivalents”. As an example, that solutions is 1.0 molar in phosphoric acid (H _{3 after 4 ), as it produces three hydrogen ions for each phosphoric acid molecule is 3.0 normal (3.0 N). Although initially it may seem advantageous to use normality instead of molarity as a standard concentration of solution, normality is not absoluteThe term but depends on the use of the solution. For this reason, the International Union of pure and applied chemistry urged the interruption of normality in expressing the concentration of solutions.}

moliality is used even less often than normality. The solution is one Molal (1.0 m) if it consists of one mole of a solut dissolved in a kilogram - not a solution - but of a solvent. Initially, it might seem that the molality does not provide any particularly valuable properties, which would be useful as a term for the concentration of solutions. However, it does not include volume, but only weight - for dissolved and solvent. This means that the molality is not dependent on the temperature, it is a unit of choice in these areas of chemistry including "coligative" properties - those properties involving the number of particles.