CHAPTER 5 Reactions in Aqueous Solution Turn in homework for Chapter 4 1 Chem 105 Chpt 4 Lsn 11 Where Road Map we were Chemical equations and chemical analysis review problems Where we are going Critical skills: naming common ions, writing electrically neutral formulas/reactions, stoichiometric conversions Types of reactions Use: Figure 5.3, page 179 Know: Table 5.2, pg 182 Chem 105 Chpt 4 Lsn 11 2 5.2 Precipitation reactions Writing Equations for Aqueous Ionic Reactions Three types of equations are used to represent aqueous ionic reactions: molecular, total ionic, and net ionic equations. molecular equation: shows all reactants and products as if they were intact, undissociated total ionic equation: shows all the soluble ionic substances dissociated into ions. Charges must balance Spectator ions not involved in chemical change. net ionic equation: it eliminates the spectator ions and shows the actual chemical change taking place. 3 Chem 105 Chpt 4 Lsn 11 Practice Problem 10-1 molecular equation Pb(NO3)2(aq) + K2CrO4(aq) → PbCrO4(s) + 2 KNO3(aq) Write the Total Ionic and Net Ionic equations for Total Net 4 Chem 105 Chpt 4 Lsn 11 Practice Problem 10-2 Write the Total Ionic and Net Ionic equations for CaCl2(aq) + Na2CO3(aq) → CaCO3(s) + 2 NaCl(aq) 5 Chem 105 Chpt 4 Lsn 11 Practice Problem 10-3 Solutions of iron (III) chloride and potassium hydroxide give iron (III) hydroxide and potassium chloride when combined. Write the Molecular equation Total ionic equation Net ionic equation 6 Chem 105 Chpt 4 Lsn 11 5.3 – Acids and Bases (know table 5.2) Acid: increases the H+ concentration Base: increases the OH- concentration Strong acid: completely dissociates/ionizes Weak acid: partial ionization 7 Chem 105 Chpt 4 Lsn 11 5.4 - Reactions of Acids and Bases An Acid reacting with a base produce a salt and water Neutralization reaction: a strong acid with a strong base 8 Chem 105 Chpt 4 Lsn 11 Practice Problem 10 - 4 Calcium chloride and potassium phosphate combine to form calcium phosphate and potassium chloride. Write the molecular equation 3 CaCl2(aq) + 2 K3PO4(aq) → Ca3PO4(s) + 6 KCl(aq) Write the Total Ionic and Net Ionic equations 9 Chem 105 Chpt 4 Lsn 11 3 CaCl2(aq) + 2 K3PO4(aq) → Ca3PO4(s) + 6 KCl(aq) Write the Total Ionic and Net Ionic equations Combining 5 grams CaCl2 with 3.5 grams of K3PO4 produced only a 67% yield of KCl. What is the limiting reactant? What mass of product did you make? 10 Chem 105 Chpt 4 Lsn 11 5.8 Measuring Concentrations How many moles of each ion are in each solution? (a) 2 mol of potassium perchlorate dissolved in water (b) 354 g of magnesium acetate dissolved in water (c) 1.88 x 1024 formula units of ammonium chromate dissolved in water (d) 1.32 L of 0.55 M sodium bisulfate 11 Chem 105 Chpt 4 Lsn 11 5.8 Measuring Concentrations How many moles of H+(aq) are present in 451 mL of 3.20 M hydrobromic acid? 12 Chem 105 Chpt 4 Lsn 11 5.4 Acid-Base Reactions: Acid-Base Titrations What volume of 0.1292 M Ba(OH)2 would neutralize 50.00 mL of the HCl solution standardized in the preceding sample problem (4.5) ? 13 Chem 105 Chpt 4 Lsn 11 Precipitation Reactions: Predicting Whether a Precipitate Will Form Predict whether a reaction occurs, and write balanced total and net ionic equations. (a) iron(III) chloride(aq) + cesium phosphate(aq) → (b) sodium hydroxide(aq) + cadmium nitrate(aq) → (c) magnesium bromide(aq) + potassium acetate(aq) → (d) silver sulfate(aq) + barium chloride(aq) → 14 Chem 105 Chpt 4 Lsn 11 Next Lesson Chapter 5 Gas forming reactions Classifying reactions Oxidation reactions Measuring concentrations of compounds in solution pH Stoichiometry of reactions in aqueous solution 15 Chem 105 Chpt 4 Lsn 11 Practice Problem 10 - 5 Write the Total Ionic and Net Ionic equations for Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g) 16 Chem 105 Chpt 4 Lsn 11 Practice Problem 10-6 Write the Total Ionic and Net Ionic equations for HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l) 17 Chem 105 Chpt 4 Lsn 11