Concentration
- To describe saturation precisely, a quantitative measure is needed - Units that measure Concentration. The important feature of all concentration measures is the ratio expressed. There are many ratios that express how much of some substance is present. Certain expressions are favored in medicine, others in pollution control, and others in biological research. Take a look the table at the below.

Concentration Units

Name	Abbr.	Units
Grams/100.g	g/100.g	g solute/100.g solvent
Mass percent	%	g solute/100.g solution
Parts per million	ppm	g solute/1000 000.g solution
Parts per billion	ppb	g solute/1000 000 000.g solution
Molarity	M	mol solute/L solution
Molality	m	mol solute/kd solvent

Molarity
- The mole is unit used to count atoms and molecules and to relate the amounts of reactants and products in chemical reactions. The mole is also the basis of the concentration measurement called Molarity.
- Molarity= mol / L
- Four labels: Molarity, Molar, M and mol/L.
- The concentration of a solution as a ratio of moles of solute per liter of solution.

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