Example hc 2 h 3 o 2 aq naoh aq molecular equation h

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Example : HC 2 H 3 O 2 ( aq ) + NaOH( aq ) Molecular Equation (H + from acid combines with OH from base to form H 2 O): Total Ionic Equation (do NOT dissociate weak acids into ions): Spectator Ions: Net Ionic Equation (omit spectator ions): Generic Net Ionic Equation:
Chem 1035 Chapter 4 35 of 53 Strong Acid + Weak Base Example : HCl( aq ) + NH 3 ( aq ) Molecular Equation (add the H + from acid to the weak base): Total Ionic Equation (do not dissociate weak bases into ions): Spectator Ions: Net Ionic Equation: Generic Net Ionic Equation:
Chem 1035 Chapter 4 36 of 53 Titrations Titration : Method of analysis in which a solution of known concentration is used to analyze a solution of unknown concentration. One solution is in a buret – the titrant. Indicator : A substance that change color when the titration reaction is complete. The indicator is used to monitor the reaction progress and indicates when the titration reaction is over. Equivalence Point: The point in the titration in which enough moles of one reactant have been added to completely react with the other reactant. The mole ratio in the balanced reaction determines this point.
Chem 1035 Chapter 4 37 of 53
Chem 1035 Chapter 4 38 of 53
Chem 1035 Chapter 4 39 of 53 Example Problem – Acid-Base Titration : A total of 32.35 mL of 0.100 M potassium hydroxide is required to neutralize 39.50 mL of sulfuric acid. What is the concentration of the sulfuric acid solution? ( M )( V ) → moles of KOH →→→ moles of H 2 SO 4 →→→ molarity of H 2 SO 4
Chem 1035 Chapter 4 40 of 53 Example Problem – Acid-Base Titration Some antacid tablets contain Mg(OH) 2 . A tablet weighing 510.0 mg is titrated, requiring 17.60 mL of 0.625 M HCl for complete titration. What is the mass percent of Mg(OH) 2 in the tablet? Balanced reaction: Strategy: ( M )( V ) to find moles of HCl; use the molar ratio to find moles of Mg(OH) 2 which is then converted to mass of Mg(OH) 2 . Divide mass of Mg(OH) 2 by tablet mass and multiply by 100. Moles of HCl: Mass of Mg(OH) 2 : Mass percent: 0
Chem 1035 Chapter 4 41 of 53 Space Shuttle Challenger tape:
Chem 1035 Chapter 4 42 of 53 OXIDATON-REDUCTION ( REDOX) REACTIONS You are surrounded by redox reactions. When you hear any of the following words, it refers to a redox reaction: Combustion of fuel Digestion of Food Batteries Metal Plating Bleaching Food spoilage Antioxidants (diseases and aging) Corrosion Electrolysis Place copper wire in aqueous solution of AgNO 3 : Cu( s ) + Ag + ( aq ) Oxidation-Reduction (Redox) Reaction = a reaction involving the exchange of electrons between two species
Chem 1035 Chapter 4 43 of 53
Chem 1035 Chapter 4 44 of 53 Every redox reaction has two half-reactions: Red = Red uction = Ag + ( aq ) + Ag( s ) Ox = Ox idation = Cu( s ) Cu 2+ ( aq ) +
Chem 1035 Chapter 4 45 of 53 Overall reaction _____ is oxidized _____ is reduced _____ is the reducing agent: the reactant causing the reduction by providing (losing) electrons _____ is the oxidizing agent: the reactant causing the oxidation by taking (gaining) electrons
Chem 1035 Chapter 4 46 of 53
Chem 1035 Chapter 4 47 of 53 ion number : number of charges an atom would have in a molecule if it
Chem 1035 Chapter 4 48 of 53 A Summary of Terminology for Redox Reactions

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