Hypermedia Integration Playlist Videos
To make it possible to just look at the playlist videos with my comments, this page was created. All videos seem to partially load so this page takes some time to load.
My notes to accompany the videos:
Le Chatelier’s Principle:
Le Chatleier’s Principle is the idea that when you add a stress to a system in equilibrium, the system will shift to relieve the stress. Cobalt chloride gives a distinctive pink or blue color depending on the ion complex that has formed. I tried to find videos that show the main ways that the equilibrium of this system can be stressed. For cobalt chloride, you can add more of the substance that appears on the left, which is usually a chloride ion, or more of a substance that appears on the right, which is usually water. Most of the equations are written so the pink form is on the left side and the blue form is on the right. So adding more chloride ions shifts the color blue, and adding water shifts the color pink. Heat also causes the equilibrium to change. Adding heat shifts the reaction toward the blue, cooling the solution shifts it toward the pink. You can also remove something on one side and cause the equilibrium to shift toward that side. For example, adding silver should cause silver chloride to precipitate to form. This pulls the chloride ions out of solution. The cobalt chloride complexes will fall apart to provide chloride ions that will fill the void created when the chloride ions that were there are pulled out of solution. So when we add a silver solution like silver nitrate, the solution should turn pink. Blue cobalt chloride ion complexes should fall apart. If I was successful with the cobalt chloride equilibrium videos, then I found one that shows what happens when there is an excess on one side, a change in temperature due to heat being added or removed, and what happens when one of the important components is removed from the solution (like binding the chloride ions with silver).
Equilibrium in cobalt(II) chloride solution
By: ChemToddler's channel
This one shows how equilibrium is restored when an excess of one of the components is added to the system.
My notes to accompany the videos:
Le Chatelier’s Principle:
Le Chatleier’s Principle is the idea that when you add a stress to a system in equilibrium, the system will shift to relieve the stress. Cobalt chloride gives a distinctive pink or blue color depending on the ion complex that has formed. I tried to find videos that show the main ways that the equilibrium of this system can be stressed. For cobalt chloride, you can add more of the substance that appears on the left, which is usually a chloride ion, or more of a substance that appears on the right, which is usually water. Most of the equations are written so the pink form is on the left side and the blue form is on the right. So adding more chloride ions shifts the color blue, and adding water shifts the color pink. Heat also causes the equilibrium to change. Adding heat shifts the reaction toward the blue, cooling the solution shifts it toward the pink. You can also remove something on one side and cause the equilibrium to shift toward that side. For example, adding silver should cause silver chloride to precipitate to form. This pulls the chloride ions out of solution. The cobalt chloride complexes will fall apart to provide chloride ions that will fill the void created when the chloride ions that were there are pulled out of solution. So when we add a silver solution like silver nitrate, the solution should turn pink. Blue cobalt chloride ion complexes should fall apart. If I was successful with the cobalt chloride equilibrium videos, then I found one that shows what happens when there is an excess on one side, a change in temperature due to heat being added or removed, and what happens when one of the important components is removed from the solution (like binding the chloride ions with silver).
Equilibrium in cobalt(II) chloride solution
By: ChemToddler's channel
This one shows how equilibrium is restored when an excess of one of the components is added to the system.
Equilibrium in cobalt(II) chloride solution - temperature
By: ChemToddler's channel
This is a quick demo to show how the equilibrium shifts due to heating cobalt chloride in the acidic solution.
By: ChemToddler's channel
This is a quick demo to show how the equilibrium shifts due to heating cobalt chloride in the acidic solution.
Chem 12 silver nitrate + CoCl4 2-
By: D Lacy
Ha! A simple, quick video that shows what happens when silver nitrate is added to cobalt (II) chloride. Love it!
By: D Lacy
Ha! A simple, quick video that shows what happens when silver nitrate is added to cobalt (II) chloride. Love it!
Le Chatelier CoCl2 Equilibrium Demonstration
By: mrsbuskey
This video is longer, but she goes through adding stresses like the chloride ion and she shows the what happens when you add silver. I don’t think she explains that the shift goes to the left because chloride ions are being pulled out of solution. She does point out the precipitate, but does not give away the “answer” that what you are seeing is silver chloride. At least the video is here so you can see what happens when silver is added to this system.
By: mrsbuskey
This video is longer, but she goes through adding stresses like the chloride ion and she shows the what happens when you add silver. I don’t think she explains that the shift goes to the left because chloride ions are being pulled out of solution. She does point out the precipitate, but does not give away the “answer” that what you are seeing is silver chloride. At least the video is here so you can see what happens when silver is added to this system.
Le Chatelier's Principle Demonstration
By: chempatenaude
While this video is long, it is actually really good at showing how the equilibrium shifts when more of the reactants are added or when one of the reactants is removed from the solution. Even though he did not add more of the product to show how that will cause a shift, because he removed one of the reactants from the solution, he forced the equilibrium to shift to the left. He did this type of demonstration twice, with two different solutions, one to pull the Fe out of solution, the other to pull the SCN out of solution. Even though the video does not have snazzy music or a very interesting personality, the science is very well done which is why I am including it in this playlist.
By: chempatenaude
While this video is long, it is actually really good at showing how the equilibrium shifts when more of the reactants are added or when one of the reactants is removed from the solution. Even though he did not add more of the product to show how that will cause a shift, because he removed one of the reactants from the solution, he forced the equilibrium to shift to the left. He did this type of demonstration twice, with two different solutions, one to pull the Fe out of solution, the other to pull the SCN out of solution. Even though the video does not have snazzy music or a very interesting personality, the science is very well done which is why I am including it in this playlist.
Le Chatelier's Principle
By: LErath1
This video is short, to the point, and has good music. Plus it uses chemicals I was not allowed to have in my classroom, like CrO4, so I could use this video to show the chromate equilibrium. I did have the NO2 tubes, though, and loved to use them. She does not mention it, but the brown clouds we see when it is warm out are because of the NO2 ó N2O4 equilibrium. When it is warm, the equilibrium shifts to the left which creates more particles in the air. I think the video was not very clear about this, but when heat is added, it should shift to the NO2, which is darker.
A good write-up for this demonstration is at: http://ncsu.edu/project/chemistrydemos/Equilibrium/NO2.pdf
Clock Reactions part 1:
Clock reactions are ones that stay a certain color and then suddenly, spontaneously change to a different color. Sometimes the color changes back, becomes another color, or stays until something is added or the reaction is altered in some physical way.
Halloween clock reaction
By: ChemToddler's channel
This video is included because it is quick and shows how the colors change after a period of time. This video can be followed up with questions such as, Why did the color change? Why did the color change at a different time for each beaker? I need to look up which reactions go to a red then a black because I don’t actually know this reaction. The video says it is a Landolt clock reaction. The time delay is because of concentration. If you are going to use this demo, read the comments section. Robbie Frank nailed it with an explanation of the chemicals and how to do the demo.
Clock reactions are ones that stay a certain color and then suddenly, spontaneously change to a different color. Sometimes the color changes back, becomes another color, or stays until something is added or the reaction is altered in some physical way.
Halloween clock reaction
By: ChemToddler's channel
This video is included because it is quick and shows how the colors change after a period of time. This video can be followed up with questions such as, Why did the color change? Why did the color change at a different time for each beaker? I need to look up which reactions go to a red then a black because I don’t actually know this reaction. The video says it is a Landolt clock reaction. The time delay is because of concentration. If you are going to use this demo, read the comments section. Robbie Frank nailed it with an explanation of the chemicals and how to do the demo.
William Tell's Iodine Clock at Stanford (11AM)
By: onefromsomewhere
This is a fantastic demonstration to do to the William Tell Overture. I chose this version of the video because you can sort-of see how the colors change with the music. You may want to look for other versions of the video. It seems to be taped for their benefit more than to provide the demo for others to learn from. I say this because other versions of the videotaping are even worse than this one- bad camera angles and the main professor keeps walking in front of the camera. He is, after all, the star because he is what allowed this demonstration to happen. Unfortunately I left the classroom before I could build an apparatus to do this demonstration. I had the materials, but not the time. I saw someone do it at an NSTA meeting where they had the solutions in syringes that fit in a board of wood. There was a hole drilled for each syringe. Another board is put on top of the syringes and someone pushes down the board so that the solutions from the syringes enter the beakers all at the same time. It is great to get the students involved, but you need much more space because human bodies take up more room than 60 mL syringes.
By: onefromsomewhere
This is a fantastic demonstration to do to the William Tell Overture. I chose this version of the video because you can sort-of see how the colors change with the music. You may want to look for other versions of the video. It seems to be taped for their benefit more than to provide the demo for others to learn from. I say this because other versions of the videotaping are even worse than this one- bad camera angles and the main professor keeps walking in front of the camera. He is, after all, the star because he is what allowed this demonstration to happen. Unfortunately I left the classroom before I could build an apparatus to do this demonstration. I had the materials, but not the time. I saw someone do it at an NSTA meeting where they had the solutions in syringes that fit in a board of wood. There was a hole drilled for each syringe. Another board is put on top of the syringes and someone pushes down the board so that the solutions from the syringes enter the beakers all at the same time. It is great to get the students involved, but you need much more space because human bodies take up more room than 60 mL syringes.
Chemical Magic - Classic Clock Reaction
By: Sick Science!
This presenter shows a few clock reactions, and explains it so it is suitable for a television audience.
By: Sick Science!
This presenter shows a few clock reactions, and explains it so it is suitable for a television audience.
Oscillating reactions:
The Traffic Light also called a Stop Light reaction is a type of oscillating reaction which means it transitions from one color to another. The sequence of colors goes in a specific direction and returns to the original color, only to repeat the sequence again.
Chemical Traffic Light - Beautiful chemical Experiment!
By: Thoisoi2 - Chemical Experiments!
This video is included because it is a good demonstration of how to do the chemical traffic light demonstration. He explains why the color changes. He uses indigo carmine as the indicator for the traffic light reaction, and ends the video with methylene blue. Metylene blue is technically the indicator used for the blue bottle reaction.
The Traffic Light also called a Stop Light reaction is a type of oscillating reaction which means it transitions from one color to another. The sequence of colors goes in a specific direction and returns to the original color, only to repeat the sequence again.
Chemical Traffic Light - Beautiful chemical Experiment!
By: Thoisoi2 - Chemical Experiments!
This video is included because it is a good demonstration of how to do the chemical traffic light demonstration. He explains why the color changes. He uses indigo carmine as the indicator for the traffic light reaction, and ends the video with methylene blue. Metylene blue is technically the indicator used for the blue bottle reaction.
Cool Science Experiment - Chemical Traffic Light
By: Abdullah Tariq
This video is included after the other chemical traffic light because this person has a different accent, and he puts some of the explanation in writing on the screen. He says that green is the oxidized state at around 19 seconds, which may not mean anything to the students yet. This, however, will let them start to connect the idea of color changes with oxidation. He does not mention what the red or yellow colors mean. Perhaps this is something they will have to learn about in class.
By: Abdullah Tariq
This video is included after the other chemical traffic light because this person has a different accent, and he puts some of the explanation in writing on the screen. He says that green is the oxidized state at around 19 seconds, which may not mean anything to the students yet. This, however, will let them start to connect the idea of color changes with oxidation. He does not mention what the red or yellow colors mean. Perhaps this is something they will have to learn about in class.
The Briggs-Rauscher Iodine Oscillator
By: mrhomescientist
This one is an Oscillator that goes through an amber color to deep blue back to amber, then to deep blue. It is more complex than the iodine clock reaction. He does a good job of explaining what is happening in the beaker, but as he says, it is really complicated.
By: mrhomescientist
This one is an Oscillator that goes through an amber color to deep blue back to amber, then to deep blue. It is more complex than the iodine clock reaction. He does a good job of explaining what is happening in the beaker, but as he says, it is really complicated.
Fantastic Four Color Oscillator
By: FlinnScientific
The Flinn videos are good, but they are long. I don’t think I found the same demo in a good, shorter video so it is included here. One good thing about buying the demo kits from Flinn is that they come with almost all of the objects you need. You’ll need to provide the hardware like graduated cylinders, but the solutions are already made for you. I did not do this demo because I don’t think I ever had Cerium. I was still a young teacher when I taught chemistry and did not make enough money to be able to buy all of my demonstration materials from Flinn. If I were in the classroom now, making what I would be making as an 18 yr teacher, I could afford to buy this one out of pocket. Just saying…
Fortunately, though, for teachers who don’t have the proper disposal area for the chemicals, we can show this video, even if only in parts with the sound muted. Since it is a Flinn video, there is an explanation included with the visual demonstration. It is showing the various oxidation states of a couple transition metals. In the last minute, she does a good job of reviewing the chemistry involved with the reactions.
By: FlinnScientific
The Flinn videos are good, but they are long. I don’t think I found the same demo in a good, shorter video so it is included here. One good thing about buying the demo kits from Flinn is that they come with almost all of the objects you need. You’ll need to provide the hardware like graduated cylinders, but the solutions are already made for you. I did not do this demo because I don’t think I ever had Cerium. I was still a young teacher when I taught chemistry and did not make enough money to be able to buy all of my demonstration materials from Flinn. If I were in the classroom now, making what I would be making as an 18 yr teacher, I could afford to buy this one out of pocket. Just saying…
Fortunately, though, for teachers who don’t have the proper disposal area for the chemicals, we can show this video, even if only in parts with the sound muted. Since it is a Flinn video, there is an explanation included with the visual demonstration. It is showing the various oxidation states of a couple transition metals. In the last minute, she does a good job of reviewing the chemistry involved with the reactions.
Blue bottle reaction
By: JCreatr
Blue bottle reactions are fun because they go from blue to colorless depending on the concentration of sugar. If you just let the bottle sit, it will become colorless. Shaking it returns the color. When I did this in the classroom, I would set up the demo and pass around the bottle. Since there is a cap on the bottle, it is safe to pass around. The time it takes to become colorless is somewhat unpredictable because the reaction gets exhausted after some time. The bottle is usually only good for one day.
Acid-Base chemistry with indicator solutions
The Rainbow Connection (Chemistry Demonstration)
By : Regan Silvestri
Rainbow Connection
By: jtgodbout
Rainbow Connection
By: Jiro Fujita
There are three Rainbow Connection videos with music because if nothing else, the music is fun to listen to. The Flinn Scientific video is included way at the bottom because they give a good explanation of what is happening, but they can’t play the music. Possibly after hearing the music twice, you can imagine it when you watch the Flinn video. The color changes here are from indicators and acid-base equilibrium reactions.
In the second demo, the beakers are larger and the colors are more prominent. Will students be able to anticipate what is supposed to happen this time since they’ve already seen the reactions once? Will they wonder why the extra stirring was needed? Can they explain what happened with the extra stirring?
The third video is good because the teacher has personality and you can see it as she acts for the students. Having a presence can be a part of doing a good demo.
The Rainbow Connection (Chemistry Demonstration)
By : Regan Silvestri
Rainbow Connection
By: jtgodbout
Rainbow Connection
By: Jiro Fujita
There are three Rainbow Connection videos with music because if nothing else, the music is fun to listen to. The Flinn Scientific video is included way at the bottom because they give a good explanation of what is happening, but they can’t play the music. Possibly after hearing the music twice, you can imagine it when you watch the Flinn video. The color changes here are from indicators and acid-base equilibrium reactions.
In the second demo, the beakers are larger and the colors are more prominent. Will students be able to anticipate what is supposed to happen this time since they’ve already seen the reactions once? Will they wonder why the extra stirring was needed? Can they explain what happened with the extra stirring?
The third video is good because the teacher has personality and you can see it as she acts for the students. Having a presence can be a part of doing a good demo.
Color in Equilibrium
By: sbmitchell2
This is another rainbow equilibrium video, but it uses a different song. It is longer because she explains how the reactions work and how to set it up as the demonstrator.
By: sbmitchell2
This is another rainbow equilibrium video, but it uses a different song. It is longer because she explains how the reactions work and how to set it up as the demonstrator.
Oxidation / Reduction reactions (REDOX)
Redox reactions are ones that happen in pairs. One of the molecules steals electrons from another molecule. The molecule that gives up the electron, is the second reaction. Oxidation is happening at the molecule that loses the electron. Reduction happens at the molecule that gains an electron. One reason reduction is called reduction because an electron is gained. Electrons have a negative charge so the charge on one of the ions in the molecule is reduced, it is made more negative. Leave it to chemistry to have backwards thinking. So losing an electron is oxidation because the ion (or molecule) is becoming more positive. The reduction is the lowering of the charge value, becoming more negative.
Redox reaction [KMnO4 + Fe]
By: Chemistry
It is very slow, but you get to see the solution become colorless. In the process it looks like metal clumps form. We know it can’t be iron because we saw the iron wires, so it seems like it would be clumps of manganese. Now that is very cool.
Redox reactions are ones that happen in pairs. One of the molecules steals electrons from another molecule. The molecule that gives up the electron, is the second reaction. Oxidation is happening at the molecule that loses the electron. Reduction happens at the molecule that gains an electron. One reason reduction is called reduction because an electron is gained. Electrons have a negative charge so the charge on one of the ions in the molecule is reduced, it is made more negative. Leave it to chemistry to have backwards thinking. So losing an electron is oxidation because the ion (or molecule) is becoming more positive. The reduction is the lowering of the charge value, becoming more negative.
Redox reaction [KMnO4 + Fe]
By: Chemistry
It is very slow, but you get to see the solution become colorless. In the process it looks like metal clumps form. We know it can’t be iron because we saw the iron wires, so it seems like it would be clumps of manganese. Now that is very cool.
Clock reactions, part 2:
This section contains primarily iodine clock reaction videos. If you feel like you already know enough about the Iodine Clock, then you can skip this section.
Iodine Clock Reaction
By: ImaginationStationOH
Humor helps when demonstrations correctly go wrong. The demonstrator knew there would be a time delay, and had fun with it. It also helps that he explains what is going on in the reaction vessels. He did a good job of emphasizing how the reaction is universal throughout the solution. The write-up with the video does a good job of explaining how this can be done safely at home.
This section contains primarily iodine clock reaction videos. If you feel like you already know enough about the Iodine Clock, then you can skip this section.
Iodine Clock Reaction
By: ImaginationStationOH
Humor helps when demonstrations correctly go wrong. The demonstrator knew there would be a time delay, and had fun with it. It also helps that he explains what is going on in the reaction vessels. He did a good job of emphasizing how the reaction is universal throughout the solution. The write-up with the video does a good job of explaining how this can be done safely at home.
Amazing Iodine Clock - Chemical Reaction
By: HouseholdHacker
The enthusiasm of the demonstrator makes this video worth the time you use to watch it. It does a good job of showing a “clock” and how a reaction can be reversed.
By: HouseholdHacker
The enthusiasm of the demonstrator makes this video worth the time you use to watch it. It does a good job of showing a “clock” and how a reaction can be reversed.
Iodine Clock Reaction
By: chssciencemaths's channel
This video reinforces the iodine clock reaction videos by explaining what is in the solutions and showing how concentration affects reaction rate. The color change indicates how fast the reactions are happening.
By: chssciencemaths's channel
This video reinforces the iodine clock reaction videos by explaining what is in the solutions and showing how concentration affects reaction rate. The color change indicates how fast the reactions are happening.
Chameleon reactions
I have no clue what chameleon reactions are, but they seem to be ones that continuously change color. There are here because it may spark some curiosity in students.
Colour change Chameleon Chemical Reaction
By: DanTheAppleMan
Color changing reaction
By: jdivis83
These two have no explanation. They are mainly here to let students see that color changes can be spontaneous.
I have no clue what chameleon reactions are, but they seem to be ones that continuously change color. There are here because it may spark some curiosity in students.
Colour change Chameleon Chemical Reaction
By: DanTheAppleMan
Color changing reaction
By: jdivis83
These two have no explanation. They are mainly here to let students see that color changes can be spontaneous.
Miscellaneous videos that are just interesting
These videos involve color changes, but I can’t figure out where they would belong in the other categories. Since they present something that is really interesting, I included them in the list.
Chemistry experiment 41 - Golden rain
By: koen2all
The color changes here are because a lead iodide precipitate forms. I imagine this is similar to “fool’s gold”, or iron pyrite. Iron pyrite is FeS2, but it is still a crystalized form of an iron compound. This would be a good demo to connect to alchemy because it looks like we made gold, or to geology because it looks similar to iron pyrite.
These videos involve color changes, but I can’t figure out where they would belong in the other categories. Since they present something that is really interesting, I included them in the list.
Chemistry experiment 41 - Golden rain
By: koen2all
The color changes here are because a lead iodide precipitate forms. I imagine this is similar to “fool’s gold”, or iron pyrite. Iron pyrite is FeS2, but it is still a crystalized form of an iron compound. This would be a good demo to connect to alchemy because it looks like we made gold, or to geology because it looks similar to iron pyrite.
Ruby Red Colloidal Gold
By: FlinnScientific
This video is here not just because a color change happens, but it is a way to bring nanotechnology into the course. By definition, nanotechnology involves things that are very tiny. Being so small, it is hard to handle things on a nanoscale in the classroom. I am left with using videos, demonstrations, or text to go over nanotechnology. Yes, it is used in some modern objects like coatings on pants or jackets to repel stains, but we can’t actually see the nanoparticles. One reason this is a good video to use is because being a Flinn Scientific video, the science is presented well and is explained during the demonstration. Some of the science involves seeing the effect of resonance in a molecule. It is also being used to show the Tyndall effect, which is a way to identify a solution as being a colloid. I suppose, it is not actually a solution because by definition a solution has no particles suspended in it. When there are particles in a real solution, they are at the bottom of the beaker as a precipitate. Unfortunately the laser demonstration is not perfect , but you can get an idea that there are particles floating in the colloidal solution. It is easy to be an armchair critic in this video, but I am grateful to have access to this information that I won’t point out what I’d do differently.
By: FlinnScientific
This video is here not just because a color change happens, but it is a way to bring nanotechnology into the course. By definition, nanotechnology involves things that are very tiny. Being so small, it is hard to handle things on a nanoscale in the classroom. I am left with using videos, demonstrations, or text to go over nanotechnology. Yes, it is used in some modern objects like coatings on pants or jackets to repel stains, but we can’t actually see the nanoparticles. One reason this is a good video to use is because being a Flinn Scientific video, the science is presented well and is explained during the demonstration. Some of the science involves seeing the effect of resonance in a molecule. It is also being used to show the Tyndall effect, which is a way to identify a solution as being a colloid. I suppose, it is not actually a solution because by definition a solution has no particles suspended in it. When there are particles in a real solution, they are at the bottom of the beaker as a precipitate. Unfortunately the laser demonstration is not perfect , but you can get an idea that there are particles floating in the colloidal solution. It is easy to be an armchair critic in this video, but I am grateful to have access to this information that I won’t point out what I’d do differently.
Review videos that are longer
These are primarily Flinn Scientific videos that are really good at explaining things. They happen to be longer than many other ones because teaching tips are often given during the video presentation. 6
Blue Bottle Experiment
By: FlinnScientific
This presenter does a thorough job of explaining what is happening with the blue bottle reaction. Be sure to look at his t-shirt because it is really useful. I love his clear vs colorless lesson. He has another indicator and shows the stop-light reaction happening, in addition to just the blue bottle.
These are primarily Flinn Scientific videos that are really good at explaining things. They happen to be longer than many other ones because teaching tips are often given during the video presentation. 6
Blue Bottle Experiment
By: FlinnScientific
This presenter does a thorough job of explaining what is happening with the blue bottle reaction. Be sure to look at his t-shirt because it is really useful. I love his clear vs colorless lesson. He has another indicator and shows the stop-light reaction happening, in addition to just the blue bottle.
The Rainbow Connection
By: FlinnScientific
This version is down here because he could not play the song for legal reasons. I still want the students to hear his explanation on what happens in the experiment. It is a bummer he had to follow the law and not violate copyright.
By: FlinnScientific
This version is down here because he could not play the song for legal reasons. I still want the students to hear his explanation on what happens in the experiment. It is a bummer he had to follow the law and not violate copyright.
Cobalt Complex Ions
By: FlinnScientific
The demonstrator explains the parts of the cobalt chloride equilibrium equation. She adds extra ions that are “loose” and are written on the left side of the reaction. Since the stress is on the left side, the equilibrium shifts right, and adding chloride ions makes the solution look a darker blue. Adding water provides more water molecules that can bind with the cobalt, so the equilibrium shifts to the left, making it look pink. The cobalt with water complex is pink. When we have more pure water, more water molecules are available to bond with the cobalt. She does not cover what happens when one of the ions is “stolen” so I had to go hunting for a video that shows what happens when something like silver nitrate is added to the cobalt chloride solutions. That video, being shorter, should go in the equilibrium of cobalt chloride section.
By: FlinnScientific
The demonstrator explains the parts of the cobalt chloride equilibrium equation. She adds extra ions that are “loose” and are written on the left side of the reaction. Since the stress is on the left side, the equilibrium shifts right, and adding chloride ions makes the solution look a darker blue. Adding water provides more water molecules that can bind with the cobalt, so the equilibrium shifts to the left, making it look pink. The cobalt with water complex is pink. When we have more pure water, more water molecules are available to bond with the cobalt. She does not cover what happens when one of the ions is “stolen” so I had to go hunting for a video that shows what happens when something like silver nitrate is added to the cobalt chloride solutions. That video, being shorter, should go in the equilibrium of cobalt chloride section.
Videos whose primary language is not English:
Principio de Le Chatelier
By elpollook
This is included because the opening frames are in Spanish (I think). Because the music is so loud you can’t actually hear them talk. It is pretty boring watching them make the solution, but for students who want to read a Spanish explanation, this may be useful. One good thing about having it heat on the platform is that you can see the purple color forming where the heat is being applied. Note: she appears to be using a thermometer as a stir rod. This is a bad idea because thermometers cost dollars and stir rods cost less than a dollar. It is better to break the least expensive equipment.
Chemistry experiment - KMnO4 + NaOH + sugar
By: Kanał użytkownika TomIRIDIUM
This one is here because it is done well and also is like the chameleon color change ones. This one is useful because in the explanation part, she tells which ion is each color. From the YouTube listing: Potassium permanganate solution changes colour when poured into sodium hydroxide and sugar solution. Colours are as follows:
- purple (MnO4- ions)
- blue (MnO4 3- ions)
- green (MnO4 2- ions)
- orange (Mn 3+ ions)
By: Kanał użytkownika TomIRIDIUM
This one is here because it is done well and also is like the chameleon color change ones. This one is useful because in the explanation part, she tells which ion is each color. From the YouTube listing: Potassium permanganate solution changes colour when poured into sodium hydroxide and sugar solution. Colours are as follows:
- purple (MnO4- ions)
- blue (MnO4 3- ions)
- green (MnO4 2- ions)
- orange (Mn 3+ ions)