Molarity of Solutions

REVIEW
Solution: homogeneous mixture where one substance is dissolved in another substance
      Solute: small quantity
      Solvent: larger quantity

We need to compare the amount of solute dissolved in a certain volume of a solution.
Molarity= number of moles of solute in one liter of a solution

FORMULA
molarity =    mass of solute    ....also known as.... M= mol
                    volume of solution                                              L


This formula can be altered so that any three of these elements can be found as long as you have the other two.

The molar concentration triangle!

Now lets look at a few examples.
Example:  If there is 5 moles of NaCl in 2.5 L of solution, what is the molar
               concentration?
M=  mol        5 mol
         L          2.5 L                        = 2 mol/L NaCl

               

How many moles of Ca(OH)2 is there in 1.30L of a .75 M solution?
         
                 M=mol/L
           = mol=ML
           = mol= (1.30L)(.75M)
                    = 0.975 (SIG. FIGS!)
                    = 0.98 mol Ca(OH)2




                 What volume in mL of 0.1 mol/L NaOH must you take to contain .030 mole of NaOH?
           
                  M= mol/L
                  L= mol/M
                  L= .030mol / 0.1 mol/L = 0.3L
                                                       = 0.3 *     1L     = 300 mL
                                                                   1000 mL

Hopefully now you understand the basics of it.  Its now time to practice!  This game includes some examples of molarity and mole conversions.  Good luck!

Billionaire-molar concentration