This is the Mg/Li electrochemical cell. The Mg/Na cell is on www.youtube.com/watch?v=dYAq.... This method follows the Standard Electrode Potential Table, as it's based on thermodynamics.
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The light at the back is shining on a bank of LEDs connected in parallel to provide a very small current but enough to microelectrolyse 0.5M CuCl₂ solution. Electrodes are carbon rods.
Chlorine reacts with KI solution. It turns blue litmus red and bleaches. It,causes starch/iodate paper to turn blue with the formation of iodine
After 10 minutes, litmus paper is almost bleached but slightly red, and the starch/iodate paper is almost white. And now 0.5M KBr has turned slightly yellow with the formation of bromine water.
After 10 minutes, the cathode shows a little copper. A 9V battery would bleach litmus in 2 minutes and show more copper, as the current would be larger.
Electrolysis of 0.5M CuCl₂ solution powered by light! NOT A BATTERY. See, the electrolysis is so slow that the litmus is actually red before bleaching. LED banks are in parallel, better than the previous tweet on this topic.
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The Beer's law plot is very good. A spreadsheet is used to find the values.
Usual values are in the 67% region.
There is absorption in the UV and blue area and the yellow-to-red region. This gives chlorophyll its green colour.
Increasing the iodine concentration does not increase the rate of reaction. Increasing the acid and propanone concentrations increases the rate of reaction.
Here is a Beer's Law plot of copper nitrate solution used to find the copper content of brass. The different coloured LEDs can show the absorption spectrum of chlorophyll. The rate of reaction of the iodination is the final slide.
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The new design is top left. The Lego cuvette holder is top right. The voltmeter is the most expensive part.
The downside is that the absorbance has to be calculated. However, a lof money has been saved for a set of 10.
There are 6 coloured LEDs and a UV LED in the experiments. Is it any good? See the next message.
Innovative design moves with new technology. The cuvette holder moves from Lego to a 3D-printed one. It uses a coloured LED as the emitter and an IR-LED as the collector. This produces a voltage related to the transmitted light.
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See how little solid is used to do this. The main video is on www.youtube.com/watch?v=FWxT....
It only takes a minute, allowing time for drawing mechanisms. Why does it form in the middle? Why does it sparkle? How is it yellow?
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Yes it much nicer to use than cabbage. Here is the pH profile. Watch my lockdown project on butterfly pea tea and more. See www.youtube.com/watch?v=tbR5...
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This is electrolysis using light. The 8 light cells are arranged in parallel to provide a voltage of about 3 V and a current of 65 mA. Copper chloride solution is electrolysed to give copper and chlorine Bleaching litmus, affecting starch/iodide paper, and potassium iodide solution.
Sustainable electrolysis using light instead of wasting the battery. Copper on the cathode
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This has a beauty of its own when projected on a screen in a lecture theatre. A diffusing complex forms when Fe(NO₃)₃ and KCNS come together. Look what happens as an Nd magnet comes close. "In a little you can see a lot."
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Go to sites.google.com/view/13ismc2....
It's about micro- and small-scale practical activities inspired by the school educators in chemistry around the world. Look at the gallery page! Sign up on the front page. Send a proposal
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Try these in a 1-1.5 cm diameter droplet of water on a polypropylene surface. Why do this? A short activity leads to a long discussion on ionic lattices, dissolving (solvation), diffusion, precipitation & spectator ions.
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Watch the ppt appear. Ca(NO₃)₂ goes in late, as it dissolves quicker. It's better to get the ppt close to the centre. This process occurs in less than a minute. It works for any precipitation, but this is a "green" version. #chemsky #chemchat #realtimechem #beyondbenign #iTeachChem #Chemistry
🌱Looking to bring green chemistry into your classroom?
Check out Nina’s Beyond Benign talk!
🎥 Watch now: youtu.be/QFAmi6us48w?...
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