Electrochemistry Lesson 4 Using Oxidation Numbers.

Slides:

Advertisements

Similar presentations

Electrochemistry Oxidation - Reduction. Table of Contents Section 1 Introduction Section 2 Oxidation Numbers Section 3 Predicting Spontaneity of a Redox.

Advertisements

Oxidation- Reduction Reaction “redox reaction”

Oxidation Reduction Reactions

Unit 7: Redox & Electrochemistry.

Standard Reference Electrode Standard Hydrogen Electrode (SHE) SHE: Assigned V Can be anode or cathode Pt does not take part in reaction Difficult.

STANDARD ELECTRODE POTENTIALS. THE STANDARD HYDROGEN ELECTRODE In order to measure the potential of an electrode, it is compared to a reference electrode.

Single displacement reactions between different metals and ions can be easily carried out in labs. The results of these experiments can be used to create.

Understanding Acid-Base and Redox Chemistry Through “Goldilocks” Diagrams William H. Myers Chemistry Department University of Richmond.

Lecture 223/19/07. Displacement reactions Some metals react with acids to produce salts and H 2 gas Balance the following displacement reaction: Zn (s)

Electrochemistry Chapter 11 Web-site:

Reduction Potential and Cells

Ch. 18 Electrochemistry Dr. Namphol Sinkaset Chem 201: General Chemistry II.

Copyright ©2009 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Introductory Chemistry, Third Edition By Nivaldo J.

Redox Reactions (con’t): eg: Al (s) + Cu 2+ (aq)  Cu (s) + Al 3+ (aq) The fact that this reaction takes place tells us that:  Cu 2+ is a stronger oxidizing.

Electrochemistry. Oxidation Numbers Electrochemical Reactions In electrochemical reactions, electrons are transferred from one species to another. In.

Balancing Redox Reactions. Steps: 1.Assign oxidation numbers 2.Write half reactions 3.Balance electrons to determine coefficients needed.

Spontaneous Redox Reactions

1 Oxidation-Reduction AKA Redox OB: Pages

Ch.9: Lesson 5 -Intro to Electrochemistry- Ch.9: Lesson 5 -Intro to Electrochemistry-

REDOX AND ELECTROCHEMISTRY Oxidation Number A. Convenient way for keeping track of the number of electrons transferred in a chemical reaction A. Convenient.

Electrochemistry Oxidation Numbers Redox Reactions Oxidizing & Reducing Agents.

Electrochemistry Lesson 4 Balancing Half Reactions.

Electrochemistry Lesson 5 Predicting Spontaneous Reactions Balancing Half Reactions.

13.2a Developing a Redox table.  the relative reactivity of metals can be used to determine which redox reactions are spontaneous In all redox reactions,

Electrochemistry Lesson 2 Strength of Oxidizing Agent Lab.

So far: Unit I. Energy Transfer: energy (heat) was moved from one substance ( the one that was hot) to another substance (the one that was cold). Unit.

For a half-reaction, the more (+) the E o red value, the greater the tendency for that reaction to “go” in that direction (i.e., reduction). Strongest.

Electrochemistry Lesson 3 Spontaneous Reactions. Predicting Spontaneous Reactions Using the Standard Reduction Chart Does Au 3+ react with Cl - ?

1 UNIT 7 Reduction / Oxidation Reactions “Redox” and Electrochemistry.

Electrochemistry Chapter 20. oxidation: lose e- -increase oxidation number reduction: gain e- -reduces oxidation number LEO goes GER Oxidation-Reduction.

Standard Reduction Potentials Its all about ~~ SHE!

Oxidation-Reduction Topic 9 Review Book.

Assigning Oxidation Numbers

Single & Double Displacement Reactions

Chapter 18: Electrochemistry

Electrochemistry #1.

Oxidation Number Practice

Oxidation Numbers Rules for Assigning Oxidation States

When magnesium burns in the presence of oxygen the octet rule explains why magnesium & oxygen come toghether. Mg has 2 valence and O has 6….

REDOX INTRODUCTION.

Oxidation Numbers Elemental form of an atom = 0

Balancing Redox Equations

Oxidation and Reduction

Single & Double Displacement Reactions

Balancing Redox Equations:

Cell Potentials and Good Batteries

Cell Potentials and Good Batteries

Activity Series Foothill Chemistry.

Electrochemistry Lesson 3 Oxidation Numbers.

Lesson 3: Spontaneity of Redox Reactions

Chapter 17 Electrochemistry

Chapter 20 Electrochemistry

Oxidation-Reduction Topic 9 Review Book.

Cell Potentials and Good Batteries

Electrochemistry Lesson 7 The Standard Hydrogen Cell.

Balancing Redox Reactions using the ½ Reaction Method

Oxidation Numbers.

Predicting Redox Reactions 9.3.

Predicting Redox Reactions 9.3.

Chapter 20 Electrochemistry

Balancing Redox Reactions Chapter 20: Day 2 and 3

Balancing Redox Equations

Lesson #2 Half Reactions

Balancing Redox Reactions

Write the oxidation numbers for each of the following:

Chapter 20: Oxidation – Reduction Reactions

Unit 9 HW Answers.

Balancing Redox Reactions using the ½ Reaction Method

What is a redox reaction?

Electrochemistry Lesson 1 Introduction.

Presentation transcript:

Electrochemistry Lesson 4 Using Oxidation Numbers

Using Oxidation Numbers If the oxidation number of the central atom increases going from left to right, its oxidation. ClO2-  ClO4- Increase is oxidation +3 +7 oxidation reducing agent 4 electrons lost

Using Oxidation Numbers If the oxidation number of the central atom decreases going from left to right, its reduction. NO3-  HNO2 +5 +3 decrease is reduction reduction 2 electrons gained oxidizing agent

Label the oxidizing agent and the reducing agent. +7 +1 +5 0 ReO4- + IO-  IO3- + Re Reduced Oxidized Ox Agent Red Agent

Label the oxidizing agent and the reducing agent. +3 +5 +5 +2 3As2O3 + 4NO3- + 7H2O + 4H+  6H3AsO4 + 4NO oxidized reduced red agent ox agent

Predicting Spontaneous Reactions Using the Standard Reduction Chart Does Au3+ react with Cl-? If it does write the spontaneous reaction.

The top reaction is written forward- reduction The bottom reaction is written in reverse- oxidation (Au3+ + 3e-  Au(s)) 2 (2Cl-  Cl2(g) + 2e-) 3 2Au3+ + 6Cl-  3Cl2(g) + 2Au(s)

Does Ag+ react with Br-?

nonspontaneous

Some ions are on both sides of the table and are oxidizing or reducing agents. For example: Fe  Fe2+  Fe3+ Sn  Sn2+  Sn4+ Cu  Cu+  Cu2+

Does Sn2+ react with Cr?

spontaneous 3 (Sn2+ + 2e-  Sn(s)) 2 (Cr(s)  Cr3+ + 3e-) Check both spontaneous 3 (Sn2+ + 2e-  Sn(s)) 2 (Cr(s)  Cr3+ + 3e-) 2Cr (s) + 3Sn2+  2Cr3+ + 3Sn(s)

Can you keep HCl in a Cu container? Explain!

nonspontaneous

Can you keep HCl in a Cu container? Explain! Yes, nonspontaneous. H+ is a weaker oxidizing agent than Cu2+ and Cu+.

Can you keep HCl in a Zn container? Explain!

Spontaneous- no H+ is a stronger oxidizing agent than Zn2+

Write the spontaneous reaction. 2H+ + 2e-  H2(g) Zn(s)  Zn2+ + 2e- 2H+ + Zn(s)  H2(g) + Zn2+

Can you keep HNO3 in a Au container? Explain!

Can you keep HNO3 in a Au container? Explain! Yes, nonspontaneous. HNO3 is a weaker oxidizing agent than Au3+.

Can you keep HNO3 in a Cu container? Explain!

Take the strongest ox agent- higher Take the strongest red agent- lower

Can you keep HNO3 in a Cu container? No, spontaneous. HNO3 is a stronger oxidizing agent than Cu2+. Write the spontaneous reaction. NO3- + 4H+ + 3e-  NO(g) + 2H2O x 2 Cu(s)  Cu2+ + 2e- x 3 2NO3- + 8H+ + 3Cu(s)  2NO(g) + 4H2O + 3Cu2+