C H E M I S T R Y Chapter 4 Reactions in Aqueous Solution

Some Ways That Chemical Reactions Occur Precipitation Reactions: Processes in which soluble reactants yield an insoluble solid product that falls out of solution. 2KNO 3 (aq) + Pb I 2 (s)Pb(NO 3 ) 2 (aq) + 2K I (aq)

Some Ways That Chemical Reactions Occur Acid-Base Neutralization Reactions: Processes in which an acid reacts with a base to yield water plus a salt. H 2 O(l) + NaCl(aq)HCl(aq) + NaOH(aq) Acid + Base  Water + Salt

Some Ways That Chemical Reactions Occur Oxidation-Reduction (Redox) Reactions: Processes in which one or more electrons are transferred between reaction partners (atoms, molecules, or ions). MgCl 2 (aq) + H 2 (g)Mg(s) + 2HCl(aq) Element + Compound  Compound + Element

Electrolytes

Electrolytes in Aqueous Solution Weak Electrolytes: Compounds that dissociate to a small extent into ions when dissolved in water. H 1+ (aq) + CH 3 CO 2 1- (aq)CH 3 CO 2 H(aq) Strong Electrolytes: Compounds that dissociate to a large extent into ions when dissolved in water. K 1+ (aq) + Cl 1- (aq)KCl(aq) Nonelectrolytes: Substances which do not produce ions in aqueous solutions. H2OH2O C 12 H 22 O 11 (aq)C 12 H 22 O 11 (s)

Electrolytes in Aqueous Solution Strong Acids: hydrochloric acid, hydrobromic acid, hydroiodic acid, perchloric acid, nitric acid, sulfuric acid.

Electrolytes in Aqueous Solution Ionic Compounds

Electrolytes in Aqueous Solution Weak acids

Electrolytes in Aqueous Solution Molecular Compounds (other than any strong or weak electrolytes)

Equations Writing Molecular Equation: All substances in the chemical equation are written using their complete formulas as if they were molecules. Ionic Equation: All of the strong electrolytes are written as ions (indicated as aq). Spectator Ions: Ions that undergo no change during the reaction and appear on both sides of the reaction arrow. Net Ionic Equation: Only the ions undergoing change are shown. Na 2 S(aq) + CuCl 2 (aq) - -> CuS(s) + 2NaCl(aq) 2Na + (aq) + S 2- (aq) + Cu(s) + 2Cl - (aq) - -> CuS(s) + 2Na + (aq) + 2Cl - (aq) 2Na + (aq), 2Cl - (aq) S 2- (aq) + Cu(s) - -> CuS(s)

Precipitation Reactions and Solubility Guidelines

Write the chemical formulas of the products (use proper ionic rules). Ag 2 CO 3 (??)AgNO 3 (aq) + Na 2 CO 3 (aq) + NaNO 3 (??) CB + ADAB + CD double replacement reaction

Precipitation Reactions and Solubility Guidelines Write the molecular, ionic, and net ionic equations for the reaction that occurs when aqueous solutions of AgNO 3 and Na 2 CO 3 are mixed.

Example Write the molecular, ionic, and net ionic equations for the reaction that occurs when aqueous solutions of FeCl 3 and Na 2 SO 4 are mixed Aqueous solution of Mg(NO 3 ) 2 and NH 4 OH

Naming Chemical Compounds Binary Acids HClhydrochloric acid HBrhydrobromic acid HFhydrofluoric acid

Naming Chemical Compounds “ate”“ic” “ite”“ous”

Examples Name the following acids A. H 2 S B. HCN C. HNO 3 D. H 3 PO 4 E. H 3 PO 3

Acids, Bases, and Neutralization Reactions H 3 O 1+ (aq) + Cl 1- (aq) HCl(aq) + H 2 O(aq) Acid (Arrhenius): A substance that dissociates in water to produce hydrogen ions, H 1+ : H 1+ (aq) + A 1- (aq)HA(aq) In water, acids produce hydronium ions, H 3 O 1+ : H 1+ (aq) + Cl 1- (aq)HCl(aq)

Acids, Bases, and Neutralization Reactions Ammonia, commonly called “ammonium hydroxide” is a base: M 1+ (aq) + OH 1- (aq)MOH(aq) Na 1+ (aq) + OH 1- (aq)NaOH(aq) NH 4 1+ (aq) + OH 1- (aq)NH 3 (aq) + H 2 O(aq) Base (Arrhenius): A substance that dissociates in water to produce hydroxide ions, OH 1- :

Acids, Bases, and Neutralization Reactions Weak acids and weak bases are weak electrolytes. Strong acids and strong bases are strong electrolytes.

Acids, Bases, and Neutralization Reactions MA + H 2 OHA + MOH These acid-base neutralization reactions are double-replacement reactions just like the precipitation reactions: or MA + HOHHA + MOH WaterAcidBaseSalt

Acids, Bases, and Neutralization Reactions Write the chemical formulas of the products (use proper ionic rules for the salt).1. Write the molecular, ionic, and net ionic equations for the reaction of aqueous HBr and aqueous Ba(OH) 2. H2OH2OHBr(aq)+Ba(OH) 2 (aq)+BaBr 2 SaltAcidBaseWater

Acids, Bases, and Neutralization Reactions Write the molecular, ionic, and net ionic equations for the reaction of aqueous NaOH and aqueous HF. Write the chemical formulas of the products (use proper ionic rules for the salt).1. Salt Acid BaseWater H2OH2OHF(aq) + NaOH(aq)+NaF

Examples Predict the product and write a molecular equation, ionic equation and net ionic equation for the following reactions K 2 CO 3 (aq) + CaCl 2 (aq) - -> HNO 2 (aq) + LiOH(aq) - -> Hbr(aq) + Mg(OH) 2 -->