1. Types of Chemical Reactions and Solution Stoichiometry

2. Solutions two parts –solutesubstance dissolved –solventsubstance doing the dissolving electrical conductivity –electrolyteconducts electricity strong electrolytemany ions available weak electrolytefew ions available –nonelectrolytedoes not allow current to flow

3. Water as a solvent dissolves many substances because of its chemistry polar covalent bond / polar molecule Hydration--process in which a salt “falls apart” partial positive (  +) charge on hydrogen is attracted to negative anions partial negative (  -) charge on oxygen is attracted to positive cations

4. Strong acids / strong bases HCl HBrGroup I cations HI(ex. NaOH, KOH) H 2 SO 4 Group II except Mg HNO 3 HClO 4 HClO 3 Completely dissociate into ions 100 molecules of HCl  100 H + and 100 Cl - NaOH (aq)  Na + + OH -

5. Weak acids /weak bases Everything that was not on the former slide. Small degree of dissociation (few ions) HC 2 H 3 O 2 (aq) H + (aq) + C 2 H 3 O 2 - (aq) NH 3(aq) + H 2 O (l) NH 4 + (aq) + OH - (aq)

6. Concentration of solutions Molarity = M = moles of solute liter of solution Calculate the molarity of a solution prepared by dissolving 1.56 g of HCl in water to make 26.8 mL of solution. 1.56 g HCl 1 mol HCl = 0.0427 mol HCl 36.5 g HCl 26.8 mL  0.0268 L 0.0427 mol= 1.59 M 0.0268 L

7. Concentrations of Ions Must decide how the substance dissociates 0.50 M Co(NO 3 ) 2 Co(NO 3 ) 2  Co 2+ + 2NO 3 - 0.50 M Co 2+ and (2 X 0.50) = 1.0 M NO 3 - Very important relationship !!!!! Liters of solution X mol = moles solute liter

8. Which of the following solutions contains the largest number of ions? 100 mL of 0.100 M NaOH 50.0 mL of 0.200 M BaCl 2 75.0 mL of 0.150 M Na 3 PO 4 0.100L X 0.100 mol NaOH =.010 mol Na + and.010 mol OH - L.050 L X.200 mol BaCl 2 = 0.010 mol Ba 2+ and 0.020 mol Cl - L 0.075 L X 0.150 mol Na 3 PO 4 = 0.034 mol Na + and 0.011 mol PO 4 3- L

9. Dilutions M 1 V 1 = M 2 V 2 How do you prepare 2.00 L of 0.50 M solution of NiCl 2 from a 1.00 M stock solution? 2.50 L X 0.50 M = ? X 1.00 M ? = 1.25 L

10. Precipitation Reactions Know your solubility rules! molecular equation overall stoichiometry but not necessarily the actual forms in solution complete ionic equation represents all ions that are strong electrolytes net ionic equation includes only the changing ions AgNO 3 + MgCl 2  AgCl + MgNO 3 Ag + + NO 3 - + Mg 2+ + 2Cl -  AgCl + Mg 2+ + NO 3 - Ag + + 2Cl -  AgCl

11. Stoichiometry for reactions in solution Determine what reaction occurs Write the balanced net ionic equation Determine which reactant is limiting Calculate moles or grams of products as needed

12. Acid-Base Reactions Decide if acid/base is strong or weak Strong acid + strong base HCl (aq) + NaOH (aq)  NaCl (aq) + HOH (l) H + + Cl - + Na + + OH -  Na + + Cl - + HOH (l) H + + OH -  H 2 O Strong acid + weak base 2HCl (aq) + Mg(OH) 2(s)  MgCl 2(aq) + 2HOH (l) 2H + (aq) + 2Cl - (aq) + Mg(OH) 2(s)  Mg 2+ (aq) + 2Cl - (aq) + 2HOH (l) 2H + (aq) + Mg(OH) 2(s)  Mg 2+ (aq) + 2HOH (l)