Molal concentration is a term used in chemistry to describe the concentration of a solution. It is spelled with a silent "a" in the first syllable, which is pronounced as /məʊləl/ in IPA transcription. The word is derived from the unit of measurement "molality," which refers to the number of moles of solute per kilogram of solvent. The correct spelling and pronunciation of this term are important for clear communication in chemical discussions and computations.
Molal concentration, also known as molality, is a term used in chemistry to describe the concentration of a solute in a solution. It is a measure of the amount of substance present in a certain mass of solvent. Molal concentration is different from molar concentration, which measures the amount of substance per unit volume of the solution.
Molal concentration is defined as the number of moles of solute present in 1 kilogram of solvent. It is usually denoted by the symbol "m". The formula to calculate molal concentration is as follows:
molality (m) = moles of solute / mass of solvent (in kg)
For example, if 5 moles of a solute are dissolved in 2 kg of solvent, the molal concentration would be calculated as:
m = 5 moles / 2 kg = 2.5 mol/kg
Molal concentration is a useful concept because it is independent of temperature and pressure, which allows for more accurate comparisons between different solutions. It is particularly important in colligative properties, such as boiling point elevation and freezing point depression, where it plays a crucial role in determining the change in these properties based on the concentration of solute particles.
In summary, molal concentration is a measure of the amount of substance present in a certain mass of solvent and is defined as the number of moles of solute per kilogram of solvent.
The word "molal" is derived from the word "mole". The term "mole" is used in chemistry to refer to a certain amount of a substance, defined as the amount of substance that contains the same number of entities (atoms, molecules, ions, etc.) as there are atoms in 12 grams of carbon-12.
The term "concenration" refers to the amount of a substance present in a given volume or mass.
When these two words are combined, "molal concentration" refers specifically to a concentration expressed in moles of solute per kilogram of solvent. It is a measure of the number of moles of solute dissolved in one kilogram of solvent.