Solution Stoichiometry

Solutions are homogeneous mixtures composed of a solute and a solvent. A solute is the chemical present in lesser amount. A solvent is the chemical present in greater amount. Chemicals that are dissolved in water are aqueous. 

Concentration can be expressed in different ways, such as g/L; mL/L; % by volume, % by mass; mol/L. The most common is mol/L which is called molarity. Another way of saying mol/L is by replacing with a capital 'M'. Another thing to note is when square brackets are involved [HCl], this is another symbol for concentration.  

Example:

• What is the concentration of sodium chloride made from 0.75mol of NaCl dissolved in 250mL of H2O?

0.75mol x     1   = 3.0mol/L = 3.0M

                 0.250L

• 25.0g of NaOH is added to 350mL of H2O. Determine [NaOH]

25.0g x 1 mol = 0.625mol = 1.79mol/L

             40.0g     0.350L