Molarity and Dilution - Professor Dave here. I want to tell you about molarity. CHORUS: (SINGING) He knows a lot about the science stuff. Professor Dave explains. - When we talk about solutions, oftentimes instead of referring to a number of moles of a particular substance, we describe concentrations. This is how many moles of the substance are present per unit volume. The unit we use for this is molarity, which means moles solute per liter of solvent, or moles per liter, denoted with a capital M. So for example, a two molar solution has two moles of solute for every liter of solvent. If we want to know the molarity of a solution and we have the grams of solute, we just convert to moles using the molar mass of the substance and divide by the total volume of the solution. We can alter the concentration of a solution by a process called dilution. This is the act of adding solvent to a solution. So if the moles of solute stay the same, it will become less concentrated as the volume increases. We make dilution calculations using this equation. Plug in the initial concentration and volume, then the final volume you will dilute to. And then solve for the new concentration. The quantities are inversely related. So we can see that doubling the volume will cut the concentration in half. Let's check comprehension. [MUSIC PLAYING] Thanks for watching, guys. Subscribe to my channel for more tutorials. And as always, feel free to email me, ProfessorDaveExplains@gmail.com [MUSIC PLAYING]