Housekeeping: Chapter 9 will take at least three weeks. There's a minimum of 8 lessons and because redox is so difficult, we will take our time. I expect an IA topic from you by Friday of this week. No excuses.
Content Review:
Textbook: Chapter 9
Links: ChemGuide Redox For Dummies Half-Equations
Agenda:
1. Housekeeping
2. Intro to Redox Reactions
Mission 1: RED-OX!!!
Mission Objectives. You should be able to:
1. Describe redox reaction in terms of electrons lost and gained.
2. Explain oxidation number and know the rules for determining oxidation numbers.
3. Contrast oxidizing agent and reducing agent.
4. Deduce the oxidation state of an atom or ion in a compound.
5. Identify species that are oxidized, species that are reduced, and spectator ions.
The definitions of oxidation and reduction have evolved over the years. They used to mean loss of oxygen/gain of oxygen. However, the definitions have become broader and we now refer to them as loss or gain of electrons. The reason for this is because many chemical processes do not include oxygen, but do undergo oxidation and reduction.
Handy little reference chart can be found HERE.
Oxidation and reduction are complementary processes. Oxidation refers specifically to the loss of electrons. Reduction refers to the gain of electrons. Transferring electrons from one substance to another leads to a flow of electrons, which is nothing but an electric current. Reversing the process (using electricity to drive redox reactions) allows for stable compounds to decompose into their component ions and elements. This process is called electrolysis. Applications of redox reactions are significant because this is the foundation for electrochemistry. Think: batteries. What would happen if there were no batteries?
Content Review:
Textbook: Chapter 9
Links: ChemGuide Redox For Dummies Half-Equations
Agenda:
1. Housekeeping
2. Intro to Redox Reactions
Mission 1: RED-OX!!!
Mission Objectives. You should be able to:
1. Describe redox reaction in terms of electrons lost and gained.
2. Explain oxidation number and know the rules for determining oxidation numbers.
3. Contrast oxidizing agent and reducing agent.
4. Deduce the oxidation state of an atom or ion in a compound.
5. Identify species that are oxidized, species that are reduced, and spectator ions.
The definitions of oxidation and reduction have evolved over the years. They used to mean loss of oxygen/gain of oxygen. However, the definitions have become broader and we now refer to them as loss or gain of electrons. The reason for this is because many chemical processes do not include oxygen, but do undergo oxidation and reduction.
Handy little reference chart can be found HERE.
Oxidation and reduction are complementary processes. Oxidation refers specifically to the loss of electrons. Reduction refers to the gain of electrons. Transferring electrons from one substance to another leads to a flow of electrons, which is nothing but an electric current. Reversing the process (using electricity to drive redox reactions) allows for stable compounds to decompose into their component ions and elements. This process is called electrolysis. Applications of redox reactions are significant because this is the foundation for electrochemistry. Think: batteries. What would happen if there were no batteries?
Mission 2: Break it in HALF!!!
Mission Objectives. You should be able to:
1. Write redox half-equations.
Let's recall the activity series of metals. It is a list of elements in order of reactivity. Metals higher on the activity series can replace metals lower than them. Below you'll see a series of half-equations and their order of reactivity, which is opposite their ease of oxidation. You have a similar chart in your Data Booklet.
Mission Objectives. You should be able to:
1. Write redox half-equations.
Let's recall the activity series of metals. It is a list of elements in order of reactivity. Metals higher on the activity series can replace metals lower than them. Below you'll see a series of half-equations and their order of reactivity, which is opposite their ease of oxidation. You have a similar chart in your Data Booklet.
Let's practice!!! See below.
Oxidizing & Reducing Agents. Oxidizing agents cause another species to be oxidized and is itself reduced in the process. Reducing agents cause another species to be reduced and is itself oxidized in the process. Let's learn more about them.
Oxidizing & Reducing Agents. Oxidizing agents cause another species to be oxidized and is itself reduced in the process. Reducing agents cause another species to be reduced and is itself oxidized in the process. Let's learn more about them.
Mission 3: Titrations Again???
Mission Objective. You should be able to...
1. Perform and analyze a redox titration
Mission Objective. You should be able to...
1. Perform and analyze a redox titration
Here is a resource from boundless.com. Hopefully we will be able to do this lab on Friday. If not Friday, definitely Monday.
This is the lab protocol we will follow. Print off a copy and have it ready by Friday. Watch this video to help prepare. Now we are not using the exact same materials, but you will have some sort of iron compound that you will dissolve into a particular volume of sulfuric acid. You will then titrate the KMnO4 into the analyte until it is colorless. One drop past this point (the endpoint) should turn the solution a light purple, which means that the iron and manganese ions have completely reacted. Perform three trials, collect your data and this will be the first lab you write up this year.
I grade your labs using the rubric given for IAs. So that means you will have to go back and do some research on redox titration and make it personable enough so that you can get personal engagement credit. If you're not sure what that entails, google it. Once I have my stuff, I'll give each of you personal copies for your reference.
This is the lab protocol we will follow. Print off a copy and have it ready by Friday. Watch this video to help prepare. Now we are not using the exact same materials, but you will have some sort of iron compound that you will dissolve into a particular volume of sulfuric acid. You will then titrate the KMnO4 into the analyte until it is colorless. One drop past this point (the endpoint) should turn the solution a light purple, which means that the iron and manganese ions have completely reacted. Perform three trials, collect your data and this will be the first lab you write up this year.
I grade your labs using the rubric given for IAs. So that means you will have to go back and do some research on redox titration and make it personable enough so that you can get personal engagement credit. If you're not sure what that entails, google it. Once I have my stuff, I'll give each of you personal copies for your reference.
Homework: Begin writing up the lab.