Electrolytes solutions

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1 Chapter 4 Types of Chemical Reactions and Solution Stoichiometry Water has a high surface tension due to hydrogen-bonding molecules attract each other more than the air. Electrolytes solutions which conduct electricity due to presence of IONS. SOLUTION UNITS (M) MOLARITY = mol solute L soln Dilution M1V1 = M2V2 2.0 M CaCl2 [Ca +2 ] = M [Cl - ] = M AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 1

Types of Chemical Reactions - Precipitation Reactions - Acid-Base Reactions - Oxidation-Reduction reactions Precipitation Reactions Complete Molecular Equation (CME) Na2SO4(aq) + BaCl2(aq) 2NaCl(aq)

2 Types of Chemical Reactions - Precipitation Reactions - Acid-Base Reactions - Oxidation-Reduction reactions Precipitation Reactions Complete Molecular Equation (CME) Na2SO4(aq) + BaCl2(aq) 2NaCl(aq) + BaSO4(s) Complete Ionic Equation (CIE) 2Na + (aq) + SO4-2 (aq) + Ba +2 (aq)+ 2Cl - (aq) 2Na + (aq) + 2Cl - (aq) + BaSO4(s) Net Ionic Equation (NIE) SO4-2 (aq) + Ba +2 (aq) BaSO4(s) Acid -Base Reactions (unbalanced) Complete Molecular Equation (CME) HCl(aq) + Ba(OH)2(aq) BaCl2(aq) + 2H2O(l) Complete Ionic Equation (CIE) Net Ionic Equation (NIE) AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 2

3 Solution Stoichiometry - Precipitates ml of a 1.50 M CaCl2 solution are reacted with 50.0 ml of a 1.00 M Na2SO4 solution a. Write the CME. b. How much solid product is formed? c. Find the concentrations of all the ions in the beaker after the reaction is complete. Ca+2 Cl1.50 M =0.150 mol L Na+ SO M = mol L Na+ CaSO4 Ca+2 Cl L total volume [Ca+2] = M [Cl-] = M [Na+]= M [SO4-2] = M AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 3

4 Solution Stoichiometry - Titration ml of a 1.50 M HCl solution are titrated with ml of a 1.00 M Ca(OH)2 solution a. Write the CME. b. How much Ca(OH)2 is needed for the titration? c. Find the concentrations of all the ions in the beaker at the equivalence point H + Cl - Ca + OH - H + OH - Ca M =0.150 mol 1.00 M = mol H2O Cl L L L total volume [Ca +2 ] = M [Cl - ] = M [H + ]= M [OH - ] = M AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 4

5 Oxidation lose e - charge gain oxygen Reduction gain e - charge lose oxygen LEO the lion says GER Oxidation Numbers 1. Ox.# of uncomb. elements = 0 (K, Cl2) 2. Charge given = ox. # (Li + ) In a compound 3. Ox. # Grp I = +1 Ox. # Grp II = Ox. # of H = +1 [except metal hydrides (NaH)] 5. Ox. # of O = -2 [except peroxides (H2O2)] 6. Ox. # of compound must add up to overall charge. (NaCl, SO4-2 ) 7. Last resort only Ox# Grp VI = -2;ox #Grp VII = -1 Ex. AgNO3(aq) + Cu(s) Cu(NO3)2(s)+Ag(s) Cl2(g) + HBr(aq) HCl(aq) + Br2(l) Ca(s) + Cl2(g) CaCl2(s) AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 5

6 Oxidation -Reduction Reactions (balancing shortcut method) In Acidic Solution [elem/e -, H2O, H + ] MnO4 - (aq) + Fe +2 (aq) Fe +3 (aq) + Mn +2 (aq) In Basic Solution [elem/e -, H2O, H +, OH - ] MnO4 - (aq) + Fe +2 (aq) Fe +3 (aq) + MnO2(aq) AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 6

7 Oxidation -Reduction Reactions (balancing - Half-reaction method) In Acidic Solution [elem/e -, H2O, H + ] Ox MnO4 - (aq) + Fe +2 (aq) Fe +3 (aq) + Mn +2 (aq) Red Overall In Basic Solution [elem/e -, H2O, H +, OH - ] Ox MnO4 - (aq) + Fe +2 (aq) Fe +3 (aq) + MnO2(aq) Red Overall AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 7

8 Redox Lab Practice The concentration of hydrogen peroxide in an aqueous solution is determined by titrating a 10.0 ml sample of this solution with the permanganate ion. If the hydrogen peroxide solution required 15.2 ml of a M KMnO 4 solution to reach the equivalence point, what is the molarity of the hydrogen peroxide solution? (The products of this reaction are Mn +2 and O 2 in acidic solution.) AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 8

9 Redox Lab Practice You Try It The concentration of bromide solution in an aqueous solution is determined by titrating a 15.0 ml sample of this solution with the permanganate ion. If the bromide solution required 22.2 ml of a M KMnO 4 solution to reach the equivalence point, what is the molarity of the bromide solution? (The products of this reaction are Mn +2 and Br 2 in acidic solution.) AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 9

10 ws-solubility Practice 1 Salt for each of the following determine if it is soluble or insoluble in water and check appropriate column at right CaCl 2 Ni(NO 3 ) 2 SrSO 4 Ba(OH) 2 KC 2 H 3 O 2 Na 2 SO 4 Zn(NO 3 ) 2 Li 2 Cr 2 O 7 ZnBr 2 Na 3 PO 3 Fe(NO 3 ) 3 LiOH PbSO 4 PbI 2 RbCN AgNO 3 Ca 3 (PO 4 ) 2 (NH 4 ) 2 S 2 O 3 AgBr Mg(NO 3 ) 2 Soluble Insoluble AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 10

11 ws-solubility Practice 2 Salt for each of the following determine if it is soluble or insoluble in water and check appropriate column at right NaCl Ba(C 2 H 3 O 2 ) 2 CuCl 2 MgBr 2 Pb(OH) 2 CaCrO 4 Mg(NO 3 ) 2 (NH 4 ) 2 CO 3 BaSO 4 Pb(C 2 H 3 O 2 ) 2 MgCO 3 Ca(ClO 3 ) 3 KNO 2 KCl KOH Na 2 CrO 4 KIO 3 Pb(C 2 H 3 O 2 ) 2 NH 4 Cl Fe(OH) 3 Soluble Insoluble AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 11

12 Demonstration - Electrolytes Compound HCl (aq) Ionic or Covalent? Polar or nonpolar? Electrolyte? HC 2 H 3 O 2 (aq) NaOH (aq) NH 3 (aq) NaCl(s) NaCl(aq) Sucrose (s) C 12 H 22 O 11 (s) Sucrose (aq) C 12 H 22 O 11 (aq) Ethanol (aq) C 2 H 5 OH AP CHEMISTRY Chapter 4 Scotch Plains-Fanwood High School Page 12

Chapter 4. Types of Chemical Reactions and Solution Stoichiometry

Chapter 4. Types of Chemical Reactions and Solution Stoichiometry Chapter 4 Types of Chemical Reactions and Solution Stoichiometry Chapter 4 Table of Contents 4.1 Water, the Common Solvent 4.2 The Nature of Aqueous Solutions: Strong and Weak Electrolytes 4.3 The Composition