R edox by ycs. Why Redox? Combination of two processes Reduction Oxidation.

Slides:

Advertisements

Similar presentations

Balancing Redox Equations in Acidic Conditions

Advertisements

Unit 20 Oxidation and reduction Activity 20.1 Investigating redox reactions Reference in textbook: Section S.

Oxidation of alcohols.

Writing ion electron half equations…. ….and balanced redox equations (……. polyatomic ions or molecules are involved….) …in acidic and neutral solutions.

9.2 Redox reactions.

Some reactions involving iodine/iodide. Potassium iodide solution (right) is colourless. Here we are about to oxidise the iodide using orange bromine.

Oxidation and Reduction

Cu 1+ Cu 2+ MnO 4 1- CrO 4 2- Cr 2 O 7 2- The presence of different ions in aqueous solution can be identified in a number of ways. One method is to.

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

Advanced Higher Chemistry Unit 1 Oxidation states of the transition metals.

1 Electrochemistry Chemical reactions and Electricity.

1.5 Oxidation and Reduction. Learning Outcomes Introduction to oxidation and reduction: simple examples only, e.g. Na with Cl 2, Mg with O 2, Zn with.

Corrosion The Chemical Process.

Manganate(V11) and Dichromate(V1) as oxidizing agents

A redox reaction is one in which the reactants’ oxidation numbers change. What are the oxidation numbers of the metals in the reaction below? 2 FeCl 3.

 Assign oxidation numbers to atoms in elements, compounds and ions.  Understand that a Roman numeral can be used to indicate oxidation states.  Writing.

Oxidised state MnO 4 - Purple (aq) Permanganate Oxidised state Cr 2 O 7 2- Orange (aq) Dichromate Reduced state Cr 3+ Green (aq) Chromium ion Oxidised.

Redox Reactions. Oxidation Reduction Oxidation and Reduction Oxidation: Gain of oxygen Loss of electrons Reduction: Loss of oxygen Gain of electrons.

1. OXIDATION REDUCTION (a) Addition of oxygen Removal of oxygen (b) Removal of hydrogen Addition of hydrogen (c) Loss of electron Gain of electron (d)

Balancing Redox Reactions Chem 12. Application of oxidation numbers: Oxidation = an increase in oxidation number Reduction = a decrease in oxidation number.

Redox Reactions. Oxidation Reduction. GCSE Oxidation: Gain of oxygen Loss of electrons Reduction: Loss of oxygen Gain of electrons Increase in oxidation.

Redox Difficult but necessary. Obviously: Oxidation is adding oxygen 2H 2 + O 2  2H 2 O Reduction is removing oxygen 2FeO + C  2Fe + CO 2 But also oxidation.

Precipitation Titrations Dr. Riham Ali Hazzaa Analytical chemistry Petrochemical Engineering.

Chapter 19 Oxidation - Reduction Reactions 19.1 Oxidation and Reduction.

Redox Reactions The corrosion of metals, especially the corrosion of iron (rusting), has a great economic impact. Rust is one of the common causes of bridge.

Study Guide, for Wed tutorial

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

Chemical Cells. Chemical Energy  Heat Energy When magnesium powder is added into copper(II) sulphate solution, the temperature of the mixture rises.

Ms Stephens Saturday, 12 December 2015 Redox Introduction Oxidation Numbers Review of Keywords Identifying Redox Reactions Common Oxidants Common Reductants.

Oxidation is an increase in oxidation number Reduction is a decrease in oxidation number H 2 + Cl 2 → 2 H Cl Notice: H 2 went from 0 to +1 (

Permanganate reactions. Manganese exists in many different oxidation states, each with a characteristic colour including: Mn VII: MnO 4 – purple Mn VI:

Redox reactions of the halogens

Unit: Electrochemistry

Chemistry NCEA L2 2.7 Redox 2013.

Oxidation/Reduction Reactions

Reduction Oxidation and Potentials. Definitions Reduction – The process of an atom or ion becoming more negatively charged –They gain electrons (which.

Oxidation-Reduction Reactions

Oxidation Numbers. Oxidation numbers Know what oxidation numbers are Understand oxidation and reduction in terms of electron transfer and changes in oxidation.

If your chemistry teacher starts to get a little flabby, you want to be sure to help fermium them up.

Redox Reactions. Oxidation Reduction GCSE Oxidation: Gain of oxygen Loss of electrons Reduction: Loss of oxygen Gain of electrons Increase in oxidation.

Redox Reactions. Oxidation Reduction GCSE Oxidation: Gain of oxygen Loss of electrons Reduction: Loss of oxygen Gain of electrons Increase in oxidation.

Chapter 8 Chemical Equations and Reactions. Types of Chemical Reactions  Direct Combination: (Synthesis) A + B  AB  Decomposition: AB  A + B  Single.

Analysing Oxidants and Reductants. What is a redox reaction? The reactant that loses electrons is oxidised Mnemonic devices OIL RIG O(xidation) I(s) L(oss.

Oxidation and reduction. Magnesium reacts with oxygen to produce magnesium oxide.

20.3 Describing Redox Equations > 1 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Chapter 20 Oxidation-Reduction Reactions.

Today’s Objectives: Define oxidation number

Chemistry 2.7 (AS 90306) Describe oxidation-reduction reactions Questions may involve any of the following: the properties of common oxidants and reductants,

Redox Reactions.

The membrane keeps the chlorine gas away

Electro Chemistry Chemical reactions and Electricity

Redox Reactions Reduction Oxidation

NCEA Chemistry 2.7 Redox AS

Chapter 6 OXIDATION & REDUCTION.

Do Now The word “Redox” comes from 2 words in chemistry (that you have come across before). Which 2 words? What do each of the words mean (GCSE definitions)

AP Chem This is our last unit!.

NCEA Chemistry 2.7 Redox AS

2.6.3 Redox Reactions of the Halogens

2.6.1 Oxidation Numbers 4/17/2019.

2.6.1 Oxidation Numbers 4/28/2019.

Redox Reactions. Reduction Oxidation.

1.5a Learning Outcomes define oxidation number, oxidation state

2.6.3 Redox Reactions of the Halogens

1.5 b Learning Outcomes apply knowledge of oxidation and reduction to explain the rusting of iron give an example of an oxidising and a reducing bleach.

AP Chem Today: Intro to last unit We will only touch basics this week.

2.6.1 Oxidation Numbers 11/5/2019.

Presentation transcript:

R edox by ycs

Why Redox? Combination of two processes Reduction Oxidation

Reduction What reduces you? Friends Parents Teachers????

Reduction In chemistry, terms associated with the reduction process are ‘OEHO!’ o xygen e lectrons h ydrogen o xidation state

Reduction L oss of oxygen G ain in hydrogen G ain of electrons D ecrease in oxidation state

Loss of Oxygen Fe 2 O 3 (s) + 3CO(g)  2Fe(s) + 3CO 2 (g) Which compound is reduced ? What is it reduced by ? termed as ‘reducing agent’

Gain in Hydrogen H 2 S(g) + Cl 2 (g)  2HCl(g) + S(s) Which compound is reduced ? What is it reduced by ? termed as ‘reducing agent’

Gain of Electrons Fe 2+ (aq) + 2e -  Fe(s) Why are the iron(II) ions reduced ?

Decrease in Oxidation State Fe 2+ (aq) + 2e -  Fe(s) Notice the state of iron changes ? From ………….to…………….? Decrease in oxidation state is REDUCTION

Oxidation Also associated with ‘OEHO!’ o xygen e lectrons h ydrogen o xidation state

Oxidation Reverse of Reduction Gain/loss of oxygen? Gain/loss of hydrogen? Gain/loss of electrons? Increase/decrease of oxidation state?

Agents R educing and O xidising agents Complicated affair

Reducing Agents Reducing agents REDUCES others but are themselves OXIDISED Examples are KI, CO, H 2 S, Metals.. Can you Name them?

Oxidising Agents Oxidising agents OXIDISES others but are themselves REDUCED Examples are FeCl 3, K 2 Cr 2 O 7, KMnO 4, H 2 O 2, O 2 Can you Name them?

Colour Changes Most of the agents undergo colour changes when they reduces or oxidises others…see your notes under Redox II for details..a MUST KNOW !

Colour Changes Oxidising agents – used to test for reducing agents e.g. Potassium permanganate : purple to colourless Potassium dichromate : orange to green Iron(III) chloride : yellow to green

Colour Changes Reducing agents – used to test for oxidising agents e.g. Potassium iodide : colourless to brown Sodium thiosulphate : changes iodine solution from brown to colourless

Activity Complete exercises in Redox I and II View this link for more informationlink