molarity

American  

[moh-lar-i-tee] / moʊˈlær ɪ ti /

noun

Chemistry.

1. the number of moles of solute per liter of solution.

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molarity British  

/ mɒˈlærɪtɪ /

noun

1. another name (not in technical usage) for concentration

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Usage

What is molarity? Molarity is the number of moles of solute per one liter of solution. The symbol for molarity is a capital M. In chemistry, a solution is a mixture of two or more substances in which neither substance changes chemically. For example, salt water is a solution that contains water (the solvent) and salt (the solute). Concentration is the amount of dissolved substance in a solution. In other words, it is the amount of stuff that has been mixed into your liquid. Concentration is usually measured in molarity. A mole is a basic unit in chemistry. It is the amount of a substance in grams that contains as many atoms, molecules, or ions as 12 grams of carbon-12 (6. 022 x 1023) does. A mole of oxygen, for example, is 6. 022 x 1023 atoms of oxygen. Molarity is the number of moles of a solute per liter of solution. If we wanted to know the molarity of our saltwater solution, we’d want to know how many moles of salt are in every 1 liter of the water.

Etymology

Origin of molarity

First recorded in 1930–35; molar ³ + -ity

Explanation

The molarity of a substance is a scientific measurement of its concentration. Molarity describes the number of moles of a solute — a dissolved substance — per liter of liquid. In chemistry, a mole is a standard unit of measurement for a chemical substance. The scientific term molarity describes the concentration of a substance, calculated as the number of moles divided by the total volume of the solution it's in. For example, a chemist might talk about the molarity of sodium chloride dissolved in water. Molarity comes from mole, which was coined by a German chemist from Molekül, German for "molecule."

Example Sentences

Then, use the molarity of the solution to calculate the volume of solution containing this molar amount of solute:

From Textbooks • Feb. 14, 2019

Likewise, the hydroxide ion molarity may be expressed as a p-function, or pOH:

From Textbooks • Feb. 14, 2019

If the solution has a density of 0.9956 g/mL, calculate the molarity of the solution.

From Textbooks • Feb. 14, 2019

A 200-mL sample and a 400-mL sample of a solution of salt have the same molarity.

From Textbooks • Feb. 14, 2019

If the density of D5W is 1.029 g/mL, calculate the molarity of dextrose in the solution.

From Textbooks • Feb. 14, 2019