Molarity and Percent Solutions

A solution with only a small cimount of solute is said to be dilute. As you may suspect, simply describing a solution as concentrated or dilute is usually about as useful as calling it pretty or nciming it Fifi. We need numbers. Two important ways to measure concentration are molarity and percent solution. 

Molcirity relates the amount of solute to the volume of the solution  

The units of molarity are always moles per liter (mol/L or rnol L ). These units are often abbreviated as M and referred to as molar. Thus, 0.25 M KOH(a 7) is described as Point two-five molar potassium hydroxide, and it contains 0.25 mol of KOH per liter of solution. Note that this does not mean that there are 0.25 mol KOH per liter of solvent (water, in this case) — only the final volume of the solution (solute plus solvent) is important in molarity. 

Like other units, the unit of molarity can be modified by standard prefixes, as in millimolar (mM, which equals 10 mol/L) and micromolar (pM, which equals 10 mol/L). 

Percent solution is another common way to express concentration. The precise units of percent solution typically depend on the phase of each component. For solids dissolved in liquids, mass percent is usually used  

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Seeking certainty about solubility Keeping tabs on molarity and percent solutions Making dilutions... 

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