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Aqueous Reactions Acids There are only seven strong acids: Hydrochloric (HCl) Hydrobromic (HBr) Hydroiodic (HI) Nitric (HNO 3 ) Sulfuric (H 2 SO 4 ) Chloric.

4 (aq)  Na 2 SO 4 (aq) + H 2 S (g) Aqueous Reactions Oxidation-Reduction Reactions An oxidation occurs when an atom or ion loses electrons. A reduction occurs when an atom or ion gains electrons. Aqueous Reactions Oxidation-Reduction Reactions One cannot occur without the other. Aqueous Reactions Oxidation Numbers To determine if an oxidation-reduction reaction has occurred, we assign an oxidation number to each element in a neutral compound or charged entity. Aqueous/


Chapter 19 Oxidation - Reduction Reactions 19.1 Oxidation and Reduction.

Chapter 19 Oxidation - Reduction Reactions 19.1 Oxidation and Reduction OxidationReduction Rules for assigning oxidation numbers 1.Most substances have the same oxidation number as their individual charge (the more electronegative element 1 st ) 2.All oxidation numbers in a compound must add up to equal the total charge on the compound 3.All single elements have a oxidation number of zero 4.All single ions have the same oxidation number as their/


Oxidation Loss of electrons. Reduction Gain of electrons.

for a polyatomic ion 8.For a covalent cmpd, the more electronegative element is assigned the negative oxidation # and vice versa Redox Reactions Involve the transfer of electrons Oxidation & Reduction Occur simultaneously. # of electrons lost = # of electrons gained. LEO goes GER LOSS of ELECTRONS = OXIDATION. GAIN OF ELECTRONS = REDUCTION Redox Reactions Single Replacement Synthesis Decomposition Recall Formats Single Replacement: element + compound  new element + new compound Synthesis: 1 product/


Oxidation and Reduction Chapter 20 INTRO TO REDOX Day 1.

Oxidation and Reduction Chapter 20 INTRO TO REDOX Day 1  A reaction in which electrons are transferred from one substance to another  Oxidation cannot occur without reductionOxidation: 1.Losing of electrons 2.Increasing the oxidation charge (0 to +1 or -2 to -1)  Reduction 1.Gaining of electrons 2.Reducing the oxidation charge (-1 to -2 or 1 to 0) Definition  Number of charges the atom would have in a/


Electrochemistry Ch.19 & 20 Using chemical reactions to produce electricity.

taken by electrons in an electrochemical cell  Describe how current flows in a voltaic cell Oxidation and Reduction  Any chemical process in which elements undergo changes in oxidation number is an oxidation-reduction reaction.  This name is often shortened to Redox reaction.  Reactions are carried out in electrochemical cells called: half cells Reduction Reaction in which the oxidation state of an element decreases  When an atom or ion gains one or more/


Monday, April 14, 2008 1.Chapter 17 Quiz 2. Notes Section 18.1 – Oxidation-Reduction 3. Homework – Reading Analysis – Section 18.1.

Oxidation-Reduction Reactions Reactions in which one or more electrons are transferred Reactions in which one or more electrons are transferred Also called Redox reactions Also called Redox reactions Oxidation is defined as the loss of electrons Oxidation is defined as the loss of electrons Reduction is defined as the gain of electrons Reduction is defined as the gain of electrons Oxidation / Reduction OIL RIG – Oxid/ and Mg gain them to become Mg? –Which metal wants to get rid of e- more? Will a Reaction /


Electrochemistry Lesson 1 Introduction. Electrochemistry Is the study of reactions that gain or lose electrons.

Electrochemistry Lesson 1 Introduction Electrochemistry Is the study of reactions that gain or lose electrons. Electrochemistry Is the study of reactions that gain or lose electrons. In this unit we will study: Battery Reactions- oxidation and reduction Corrosion- oxidation Preventing Corrosion Oxidation Electroplating- reduction Refining Metals- reduction Oxidation means loss of electrons LEOLossElectronsOxidation Oxidation Half Reactions show how Metals or Anions lose electrons metalion Balance charge Add/


OxidationReduction Mr. Chan Northwestern University To insert your company logo on this slid From the Insert Menu Select “Picture” Locate your logo.

key before using the resize handles, you will maintain the proportions of the object you wish to resize. Defining Redox Oxidation - reduction  Originally combining with oxygen  Reduction – originally meant loss of oxygen Oxidation – loss of electrons Reduction – gain of electrons  OILRIG Oxidizing and Reducing Agents  Red. Agent – loses electrons, gets oxidized  Ox. Agent – gains electrons, gets reduced Practice 1-2 Corrosion – some metals corrode faster than others Determining/


1 4.9 Oxidation-Reduction Reactions lRedox reactions- reactions in which one or more electrons is transferred.

1 4.9 Oxidation-Reduction Reactions lRedox reactions- reactions in which one or more electrons is transferred 2 4.9 Oxidation-Reduction Reactions Oxidation and Reduction lWhen a metal undergoes corrosion it loses electrons to form cations: Ca(s) +2H + (aq)  Ca 2 + (aq) + H 2 (g) lOxidized: atom, molecule, or ion becomes more positively charged. /


RedOx Chapter 18. Oxidation- Reduction Reactions Redox or oxidation-reduction reactions are reactions that involve a transfer of electrons. Oxidation.

must have lost 2 electrons 2 Na → 2Na + + 2 e - And Hydrogen gained two electrons 2 H 2 O +2 e - → 2 OH - + H 2 Sodium is oxidized, hydrogen is reduced in this reaction Oxidation is an increase in oxidation state Reduction is a decrease in oxidation state Balancing Redox Equations by Half Reactions Method Balancing Equations Redox reactions don’t follow normal rules for balancing equations because we/


ELECTROCHEMISTRY Chapter 20

) LEO (the lion) goes GER Losing Electrons Oxidation, Gaining Electrons Reduction OLE- Oxidation Losing Electrons But now feeling positive Oxidized is cool! Oxidation Haiku! Lost an electron But now feeling positive Oxidized is cool! OXIDATION-REDUCTION REACTIONS Direct Redox Reaction Oxidizing and reducing agents in direct contact. Cu(s) + 2 Ag+(aq) ---> Cu2+(aq) + 2 Ag(s) Copper + Silver Ion OXIDATION-REDUCTION REACTIONS Indirect Redox Reaction A battery functions by transferring electrons through an/


Oxidation-Reduction Reactions “Redox”

Reducing Agents and Oxidizing Agents The substance reduced is the oxidizing agent The substance oxidized is the reducing agent Sodium is oxidized – it is the reducing agent Chlorine is reduced – it is the oxidizing agent Trends in Oxidation and Reduction Active metals: Lose electrons easily Are easily oxidized Are strong reducing agents Active nonmetals: Gain electrons easily Are easily reduced Are strong oxidizing agents Redox Reaction Prediction #1 Important Oxidizers Formed in reaction MnO4/


Electro Chemistry Unit 5 Chemistry 12.

+ ions Base donates OH- ions Bronstead-Lowery : Acid proton donor Base proton accepter Lewis : Acid is an electron pair accepter Base an electron pair donor Electro Chemical Reactions 2 types (oxidation and reduction) Oxidation 1/2 reaction in which the reacting species looses an electro Reduction 1/2 reaction in which the reacting species gains an electron Memory Trick “LEO the lion says GER” LEO: loss of electrons/


Chapter 20. Calculating Oxidation Numbers Each oxide ion has a charge of -2 7 oxide ions have a subtotal charge of -2 x 7 = -14 Since the formula has.

= +7 This compound is manganese(VII) oxide Work oxidation numbers of Cr and S in Cr 2 (SO 4 ) 3 (Hint: treat SO 4 2- as a single particle) Oxidation -Reduction Reactions I Play Video On YouTube Oxidation - Reduction Reactions II Play Video On YouTube Common Oxidation States Play Video On YouTube Cu 2+ + Fe 0 Redox Reaction Play Video In YouTube CuO + C Redox Reaction Play Video On YouTube Mercury (II/


Energy. Laws of Thermodynamics Flow of Energy in Living Things –Oxidation & Reduction Free Energy: Endergonic & Exergonic Rxs. Activation Energy Enzymes.

Things Oxidation - Reduction Oxidation atom/molecule loses an electron. Reduction atom or molecule gains an electron. Redox reactions - electron lost must be gained Fig. 8.4 (TEArt) Gain of electron  reduction Low energy e–e– AB High energy Loss of electron (oxidation)/GlucoseFructose Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Enzyme Structure and Function What do enzymes do? Bring molecules together Orients molecules in correct position Strains (bends) /


Galvanic Cells What will happen if a piece of Zn metal is immersed in a CuSO 4 solution? A spontaneous redox reaction occurs: Zn (s) + Cu 2 + (aq) Zn 2.

the electrode platinum foil Galvanic Cells Zn (s) + 2 H + (aq) Zn 2+ (aq) + H 2 (g) Oxidation half-reaction: Zn (s) Zn 2+ (aq) + 2 e - Reduction half-reaction: 2 H + (aq) + 2 e - H 2 (g) In this case a standard hydrogen electrode is used as the cathode/ reduction half- reactions, identify the metal at the anode, the balanced reaction for the galvanic cell, and the E o cell. Al 3+ (aq) + 3 e - Al (s) E o red = -1.66 V Fe 2+ (aq) + 2 e - Fe (s) E o red = -0.440 V Galvanic Cells Oxidizing Agent (oxidant):/


Balancing Oxidation- Reduction Reactions Any reaction involving the transfer of electrons is an oxidation-reduction (or redox) reaction.

- + C 2 O 4 2-  Cr 3+ + CO 2 2[Cr +6 + 3e -  Cr +3 ] 2[C +3  C +4 + 1e - ] Balancing Oxidation-Reduction Reactions: Balancing Oxidation-Reduction Reactions: 3. Take into account any subscripts in the formulas of reactants and products, and multiply the half reactions accordingly. Cr 2 O 7 2- + C 2 O 4 2-  Cr 3+ + CO 2 2Cr +6 + 6e -  2 Cr +3 2C/


Electrochemical Reactions Redox reaction: electrons transferred from one species to another Oxidation ≡ loss of electrons Reduction ≡ gain of electrons.

Electrochemical Reactions Redox reaction: electrons transferred from one species to another Oxidation ≡ loss of electrons Reduction ≡ gain of electrons What is reduced is the oxidizing agent H + oxidizes Zn by taking electrons from it What is oxidized is the reducing agent Zn reduces H + by giving it electrons Oxidation and Reduction Zn (s) + CuSO 4 (aq) ZnSO 4 (aq) + Cu (s) Zn is oxidized; Zn is reducing agentZn Zn 2+ + 2e - Cu/


Oxidation-Reduction Reactions

Oxidation-Reduction Reactions (Redox Reactions) Oxidationreduction reactions (REDOX) - The chemical changes that occur when electrons are transferred between reactants. Assigning Oxidation Numbers Ox# of element is zero. Sum of ox#’s is zero. If covalent, more EN element is negative. Oxygen is usually a -2, except peroxides where it is -1 or when it is electropositive and a +2 Ex: Fe0 Cu0 O20 Ex: CaBr2 +2 -1(2) = 0/


Lecture 11: Electrochemistry Introduction

: electrons are neither created or destroyed during a redox reaction. They are transferred from the species being oxidized to that being reduced. Example Identify the species being oxidized and reduced in the following (unbalanced) reactions: ClO3- + I- I2 + Cl- reduction +5 -1 0 -1 oxidation NO3- + Sb Sb4O6 + NO reduction +5 0 +3 +2 oxidation Balancing Redox Reactions One method of half reactions Key idea….make sure e- are neither created/


CHE-300Review nomenclature syntheses reactions mechanisms.

Syntheses 1. reduction of alkene (addition of hydrogen) 2. reduction of an alkyl halide a) hydrolysis of a Grignard reagent b) with an active metal and acid 3. Corey-House Synthesis Reactions 1. halogenation 2. combustion (oxidation) 3. pyrolysis/alkyl halide 2. dehydration of an alcohol 3. dehalogenation of a vicinal dihalide 4. reduction of an alkyne reactions 1. addition of hydrogen10. hydroboration-oxidation 2. addition of halogens11. addition of free radicals 3. addition of hydrogen halides12. /


OXIDATION- REDUCTION REACTION REVIEW. Oxidation-Reduction (“Redox”) Reactions Most common reaction Process often written as two “half-reactions”—separating.

of electrons in element Compound becomes more NEGATIVE DECREASE in oxidation number 2) Oxidation LOSS of electrons Compound becomes more POSITIVE INCREASE in oxidation number Oxidation and Reduction MUST happen together—can’t have one without the other. electrons gained = electrons lost Example 1: 2Na + Cl 2  2Na + Cl - Practice Which equations are reduction half-reactions and which are oxidation half-reactions. 1) Zn +2 + 2e -  Zn 2) Ag  Ag + + e/


Chapter 15. Oxidation-Reduction Reactions

  2 Cr3+ + 7 H2O 2 F1(aq)  F2(g) + 2 e1 Oxidation-Reduction Reactions In ionic compounds, we can look at changes in charge to figure out whats reduced and whats oxidized. What happens with molecular compounds? CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(g) Use Oxidation Numbers Determining Oxidation Numbers An oxidation number (or oxidation state) is the charge that an atom appears to have when/


Lecture 16 The Redox Reactions Oxidation State Half-Reactions Balanced Oxidation-Reduction reactions Predicted Sequence of Redox Reactions Tracers for.

an electron acceptor. Thus: Ox1 + Red2 = Red1 + Ox2 In this case Red2 is the electron donor, passing electrons to Ox1 which is the electron acceptor. Thus Red2 is oxidized to Ox2 and Ox1 is reduced to Red1. The equilibrium constant for an oxidation-reduction reaction can be determined by combining the constants from Table 1 as follows for O 2 with glucose The two half/


CHE-300Review nomenclature syntheses reactions mechanisms.

Syntheses 1. reduction of alkene (addition of hydrogen) 2. reduction of an alkyl halide a) hydrolysis of a Grignard reagent b) with an active metal and acid 3. Corey-House Synthesis Reactions 1. halogenation 2. combustion (oxidation) 3. pyrolysis/alkyl halide 2. dehydration of an alcohol 3. dehalogenation of a vicinal dihalide 4. reduction of an alkyne reactions 1. addition of hydrogen8. hydroboration-oxidation 2. addition of halogens9. addition of free radicals 3. addition of hydrogen halides10. /


Chapter 18 OxidationReduction Reactions and Electrochemistry.

15 1.Identify and write the equations for the oxidation and reduction half – reactions. 2.For each half – reaction: A.Balance all the elements except H and O. B.Balance O using H 2 O. C.Balance H using H +. D.Balance the charge using electrons. The Half–Reaction Method for Balancing Equations for OxidationReduction Reactions Occurring in Acidic Solution Section 18.4 Balancing OxidationReduction Reactions by the Half-Reaction Method Return to/


Unit 6 Oxidation/Reduction and Electrochemistry November 28, 2014.

Unit 6 Oxidation/Reduction and Electrochemistry November 28, 2014 Redox Chemistry Redox (reduction/oxidation) chemistry deals with chemical reactions in terms of electron transfer. The terminology comes from the reactions metals undergo. Reduction Reactions: Reduction reactions were originally associated with a loss of mass in metal ores upon heating or reacting with carbon: Reduction of tin (IV) oxide to tin metal: Δ SnO 2 (s) + C (s) Sn (s) +CO 2 (g) 150.7 g/


Ch. 20 Oxidation-Reduction Reactions. Types of Reactions There are many different types of reactions: 1.Redox 2.Acid-Base 3.Precipitation.

Ch. 20 Oxidation-Reduction Reactions Types of Reactions There are many different types of reactions: 1.Redox 2.Acid-Base 3.Precipitation 20.1 Oxidation and Reduction Oxidation- Reduction Reaction: reaction in which electrons are transferred from one atom to another AKA- Redox Reaction Oxidation The roaring fire shown to the right is an example of the rapid oxidization of the hydrocarbons making up the wood and the reduction of the Oxygen gas from the air. The, very/


Redox Reactions Or How Batteries Work REDOX Reactions The simultaneous transfer of electrons between chemical species. – Actually 2 different reactions.

is more active than copper. Cu + ZnSO 4 No Reaction Copper cannot replace zinc Oxidation is on top Reduction is on bottom Review of Terms oxidation-reduction (redox) reaction: – involves a transfer of electrons from the reducing agent to the oxidizing agent. oxidation: loss of electrons reduction: gain of electrons Half-Reactions The overall reaction is split into two half-reactions, one involving oxidation and one reduction. 8H + + Mn +7 O 4  + 5Fe 2+  Mn/


Carboxylic Acids Carboxylic Acids  Nomenclature  Properties  Preparation reactions  Typical reactions  Spectroscopy.

u From Primary Alcohols u From Aldehydes u From Substituted Aromatics Carbonation of Grignard Reagents Hydrolysis of Acid Derivatives and Nitriles Haloform Reaction Cleavage of methyl carbinols Cleavage of methyl carbonyls Periodic Acid Cleavage of Vicinal Dials/Diketones Oxidative Cleavage Reactions Oxidative Cleavage Reactions  Alkene Cleavage  Hot Potassium Permanganate  Alkyne Cleavage  Hot Potassium Permanganate  Ozonolysis  Alkene Cleavage  Hot Potassium Permanganate  Alkyne Cleavage  Hot/


Electrochemistry and Redox Reactions. 2Mg (s) + O 2 (g) 2MgO (s) 2Mg 2Mg 2+ + 4e - O 2 + 4e - 2O 2- Oxidation half-reaction (lose e - ) Reduction half-reaction.

Electrochemistry and Redox Reactions 2Mg (s) + O 2 (g) 2MgO (s) 2Mg 2Mg 2+ + 4e - O 2 + 4e - 2O 2- Oxidation half-reaction (lose e - ) Reduction half-reaction (gain e - ) 19.1 Electrochemical processes are oxidation-reduction reactions in which: the energy released by a spontaneous reaction is converted to electricity or electrical energy is used to cause a nonspontaneous reaction to occur 002+2- Oxidation number The charge the atom would have/


Solution Reactions 1. Electrolytes – Completely Break up into ions in water (Arrhenius, 1884 (Nobel Prize, 1903)). a. Many Ionic Compounds and strong acids.

Reactions 2.Modern Definition –decrease (reduction) in oxidation number N 2 + 3H 2  2NH 3 0 -3 N was reduced Reduction Solution Reactions Example In the following rxns, which element is oxidized,/Reactions Will aqueous iron(II)chloride oxidize magnesium metal? Solution Reactions Can aluminum foil reduce Fe(NO 3 ) 2 to iron metal? Solution Reactions Can aluminum foil react with HCl? Solution Reactions Which of the following metals will be oxidized by Pb(NO 3 ) 2 : Zn, Cu, and/or Fe? Solution Reactions/


Redox Reactions This is a oxidation-reduction reaction where the transfer of electrons from a reductant to an oxidant occur. Oxidation- is the loss of.

Reactions This is a oxidation-reduction reaction where the transfer of electrons from a reductant to an oxidant occur. Oxidation- is the loss of electrons therefore this element is being reduced. (reductant) Reduction- is the gain of electrons therefore this element is being oxidised. (oxidant) Oxidation Like acid-base reactions, redox reactions are a matched set - you dont have an oxidation reaction without a reduction reaction happening at the same time. So we call these half cell reactions/


Oxidation-Reduction Reactions. Oxidation and Reduction Oxidation-reduction reactions always occur simultaneoulsy. Redox Reactions Oxidation Loss of electrons.

Oxidation-Reduction Reactions Oxidation and Reduction Oxidation-reduction reactions always occur simultaneoulsy. Redox Reactions Oxidation Loss of electrons Gain oxygen 2Fe 2 O 3 + 3C 2  4Fe + 3CO 2 Reduced Oxizided Reduction Gain Electrons Loss of Oxygen Redox Reactions that Form Ions Between metal and nonmetals, electrons are transferred from the metal to the nonmetal. Increases stability Mg + S  Mg 2+ + S 2- Oxidation: Mg  Mg 2+ + 2e - (loss of electrons) Reduction: S + 2e -  S 2- (gain/


Aqueous Reactions CHAPTER 20 “Oxidation-Reduction Reactions” LEO SAYS GER.

Aqueous Reactions CHAPTER 20 “Oxidation-Reduction Reactions” LEO SAYS GER Aqueous Reactions Oxidation-Reduction Reactions An oxidation occurs when an atom or ion loses electrons. A reduction occurs when an atom or ion gains electrons. Aqueous Reactions Oxidation and Reduction (Redox) Redox currently says that electrons are transferred between reactants Mg + S → Mg 2+ + S 2- The magnesium atom (which has zero charge) changes to a magnesium ion by losing 2 electrons, and is oxidized to Mg/


Oxidation & Reduction IB Topics 9 & 19 AP Chapters 4.9-4.10; 17.

Cr 3+ 4+ 14H 2 O28H + +12e - + Redox Balancing Practice Balance the following redox rxn that takes place in acidic sol’n: Now add the oxidation and reduction reactions together: C 2 H 5 OH  CO 2 2 3H 2 O + + 12H + + 12e - Cr 2 O 7 2-  Cr 3+ 4+/- (aq) + 2H 2 O (l) =4H 2 O (l) + 4e - Redox Balancing Practice Balance the following redox rxn that takes place in acidic sol’n: Now add the oxidation and reduction reactions together: CN - (aq) + 4Ag (s)  4Ag(CN) 2 - (aq) 8 O 2 (g)  2H 2 O (l) 4H + (aq) +4e - + /


Understand Redox reactions involve a transfer of electrons. Develop a metals activity series experimentally. Predict spontaneous reactions using an activity.

. Develop a metals activity series experimentally. Predict spontaneous reactions using an activity series. Burning and corrosion needs oxygen – oxidation. Oxidation-reduction reactions – (redox) Chemical changes when electrons are transferred from one reactant to another. Oxidation - an atom loses one or more electrons. Reduction - an atom gains one or more electrons. "LEO says GER” Losing Electrons is Oxidation, Gaining Electrons is Reduction Atoms fight for electrons. The strongest takes electrons from/


Applications of Redox Electrochemistry. Review Oxidation reduction reactions involve a transfer of electrons. OIL-RIG Oxidation Involves Loss Reduction.

with oxygen in the air at high temperatures to form lead (II) oxide and sulfur dioxide. Which substance is a reluctant (reducing agent) and which is an oxidant (oxidizing agent)? A. PbS, reductant; O 2, oxidant B. PbS, reductant; SO 2, oxidant C. Pb 2+, reductant; S 2-, oxidant D. PbS, reductant; no oxidant E. PbS, oxidant; SO 2, reductant Balancing Redox Reactions by ½ Reactions –Acidic Potassium dichromate is a bright orange compound that can be reduced/


Electron-transfer reactions are called oxidation-reduction reactions or redox reactions. Oxidation – loss of electrons by one reactant. Reduction – gain.

Electron-transfer reactions are called oxidation-reduction reactions or redox reactions. Oxidation – loss of electrons by one reactant. Reduction – gain of electrons by another reactant. Oxidation and reduction always occur together. Na → Na + + e - (oxidation) Cl 2 + 2e - → 2Cl - (reduction) The substance that is oxidized is the reducing agent. The substance that is reduced is the oxidizing agent. Oxidation Is Losing e - Reduction Is Gaining e - =OIL RIG Oxidation numbers provide a way to keep tabs on /


Unit 16 Electrochemistry Oxidation & Reduction. Oxidation verses Reduction Gain oxygen atoms 2 Mg + O 2  2 MgO Lose electrons (e - ) Mg (s)  Mg + 2.

is measured in Amperes. 1 Amp = 6.0 x 10 18 e - /s An electrochemical Cell (Galvanic or voltaic cell) is a chemical device to make electricity from chemical reactions. It employs oxidation and reduction. It will have a positive (+) voltage while it works. Cell Potential (E o cell ) or Electromotive force (emf) is the pull or “driving force” on the e -. It is/


Reduction- Oxidation Reactions (1) 213 PHC 9 th lecture Dr. mona alshehri (1) Gary D. Christian, Analytical Chemistry, 6 th edition. 1.

electrochemical cells. 4 electrochemical cells Galvanic cells Electrolytic cells ◦ Galvanic cells  A spontaneous reaction occurs and produce electrical energy. ◦ Electrolytic cells  Electrical energy is used to force a non- spontaneous reaction to occur. 5 Both cells contain electrodes where the oxidation and reduction reactions occur:electrodes Oxidation occurs at the electrode called the anode. Reduction occurs at the electrode called the cathode. Electrons flow from the anode to the/


REDOX Reactions. Redox means… OxidationReduction Reactions Redox Rxns involve the… Complete or partial transfer of electrons Change in Oxidation Numbers.

super complex, so we have a special way to balance them… How?? Use HALF REACTIONS!! What is a half reaction you say?? The idea behind using half reactions is simple:  They are reactions that show oxidation and reduction separately. Then, they can be combined (or added together) to give the overall, BALANCED, redox reaction But…prepare yourself, there are a lot of rules & it can be confusing….you/


Electrochemistry Chapter 17 “Leo” the lion says “ger” §LEO - Lose Electrons = Oxidation GER - Gain Electrons = Reduction §What are the half reactions.

Electrochemistry Chapter 17 “Leo” the lion says “ger” §LEO - Lose Electrons = Oxidation GER - Gain Electrons = Reduction §What are the half reactions of l Mg(s) + 2H + (aq)  Mg 2+ (aq) + H 2 (g) ? § Mg(s)  Mg 2+ (aq) + 2e - l 2H + (aq) + 2e -  H 2 (g) Galvanic Cell §Which is the oxidation and which is the reduction? Mg(s)  Mg 2+ (aq) + 2e - 2H + (aq) + 2e -  H/


CVEN 5424 Environmental Organic Chemistry Lecture 24 – Redox Reactions: Reduction.

—SH  R—SO 3 - Generally, the reverse of the reduction reactions Oxidation ReactionsOxidation requires electron acceptors  natural waters  oxygen O 2 (actually, the superoxide radical)  radicals (hydroxy OH  -, peroxide, peroxy)  nitrate NO 3 -  Fe(III) and Mn(IV) (aqueous and mineral)  sulfate SO 4 2-  disinfection  hypochlorous acid HOCl, chloramine H 2 NCl, ozone O 3  “wet” oxidation  persulfate (S 2 O 8 2- ), S(VI)  permanganate/


CVEN 5424 Environmental Organic Chemistry Lecture 24 – Redox Reactions: Reduction.

1,2-diiodoethane0.42.66216 << slowestfastest Reduction Reactions  Predicting kinetics – one example Reductive dehalogenation k R  bond strength and electron withdrawal BS: C—X bond strength/reduction of organic contaminants oxidation of reductants Reduction Reactions  Zero-valent iron  permeable reactive barrier remediation  other metals also (Sn, Zn, etc.)  iron metal is oxidized  “rusting”  corrosion  Fe 0 = Fe 2+ + 2 e -  E H 0 (W) ~ -0.6 V  Promotes reductive dechlorination Reduction Reactions/


Reactions of aldehydes and ketones : oxidation reduction nucleophilic addition 1)Aldehydes are easily oxidized, ketones are not. 2)Aldehydes are more reactive.

Reactions of aldehydes and ketones : oxidation reduction nucleophilic addition 1)Aldehydes are easily oxidized, ketones are not. 2)Aldehydes are more reactive in nucleophilic additions than ketones. Aldehydes & ketones, reactions: 1)Oxidation 2)Reduction 3)Addition of cyanide 4)Addition of derivatives of ammonia 5)Addition of alcohols 6)Cannizzaro reaction 7)Addition of Grignard reagents 8) (Alpha-halogenation of ketones) 9) (Addition of carbanions) 1) Oxidation Aldehydes (very easily oxidized!) CH/


Chapter 21 - Oxidation-Reduction Reactions 2: 38.40/49 = 78.37% 3: 40.36/49 = 82.37%

shared But H-O-H, oxygen pulls electrons towards it So the oxygen partially gains electrons, making it reduced And the hydrogens partially lose electrons, making them oxidized Summary Processes Leading to Oxidation and Reduction OxidationReduction Complete loss of electrons (ionic reactions) Complete gain of electrons (ionic reactions) Shift of electrons away from an atom in a covalent bond Shift of electrons towards an atom in a/


Introduction to Oxidation-Reduction Reactions

: Acid/Base Precipitation/Solubility Complex Formation/Complex Dissociation Oxidation/Reduction Any chemical reaction consists of one (or more) of these basic categories. Oxidation/Reduction Reactions Acid/Base reactions involve a donation /acceptance of protons Precipitation/ Solubility reactions involve a donation/ acceptance of negative charge what is being donated and accepted in a redox reaction? Oxidation/Reduction Reactions Electrons! Consider the reaction taking place in a disposable battery: 2Zn/


Chapter 18 Electrochemistry.

5Fe3+ + 4H2O Half–Reactions The overall reaction is split into two half–reactions, one involving oxidation and one reduction. 8H+ + MnO4- + 5Fe2+  Mn2+ + 5Fe3+ + 4H2O Reduction: 8H+ + MnO4- + 5e-  Mn2+ + 4H2O Oxidation: 5Fe2+  5Fe3+ + 5e- Copyright © Cengage Learning. All rights reserved For each half–reaction: The Half–Reaction Method for Balancing Equations for OxidationReduction Reactions Write separate equations for the oxidation and reduction half–reactions. For each half–reaction: Balance all the/


Electrochemistry Lesson 1 Introduction. Electrochemistry Is the study of reactions that gain or lose electrons.

It is simpler to write the net ionic equation. 1.Al+Zn(NO 3 ) 2 Al Al 3+ +3e - oxidation Redox Reactions Both oxidation and reduction must occur. The number of electrons gained must be equal to the number of electrons lost. It is simpler to write the/write the net ionic equation. 1.Al+Zn(NO 3 ) 2 2(Al Al 3+ +3e - )oxidation 3(Zn 2+ +2e - Zn)reduction Balance electrons Redox Reactions Both oxidation and reduction must occur. The number of electrons gained must be equal to the number of electrons lost. It is /


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