Solution Stoichiometry

I.  SOLUTIONS

                A. Solutions are homogeneous mixtures composed of a solute and a solvent

                                a. Solute: The chemical present in lesser amount

                                                1. Whatever is being dissolved

                                b. Solvent: The chemical present in greater amount

                                                2. Whatever does the dissolving

                B. Chemicals dissolved in water are aqueous (aq)

II. MOLARITY

                A. Concentration can be expressed in many different ways

                                a. Ex. g/L, mL/L, % by volume, % by mass, mol/L

                                b. The most common is mol/L (M), which is also called molarity

                                                1. mol/L = M

                                                2. [HCl] = find the concentration of HCl

EX.  What is the concentration of 0.118 mol of water in 2.50 L?

0.11 x (1 mol/ 2.50 L) = 0.047M

EX. A solution of Pb(NO₃)₂ has a concentration of 0.330M. How many moles of solute are contained in 100 mL?

(0.330 mol/L) x (0.100L/ 1) = 0.0330 mol

EX. Determine the concentration of 12.5g of PbCl₂ in 30mL of water

12.5g x (1 mol/ 278.2g) x(1/ 0.030L) = 1.5M

EX. What volume of 12.7M  HNO₃ would be needed to produce  25.0g of HNO₃?

(1L/ 12.7 mol) x (25g/ 1) x (1 mol/ 63 g) = 0.031 L

-Nicole