Bob Worley
@bobthechemist.bsky.social
370 followers 340 following 29 posts
Author of Understanding Chemistry through Microscale Practical Work. Can do the Traditional stuff as well but the educational, pedagogical, economical & environmental advantages of micro & small-scale techniques (MaSSTs) are becoming increasingly relevant.
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bobthechemist.bsky.social
You can watch this method of filtering on youtu.be/6rSu-blfRZo. This is separating activated carbon from an aqueous suspension. Carbon was used to remove a dye.
This is separating activated carbon from an aqueous suspension.
bobthechemist.bsky.social
Atmospheric chemistry is difficult for schools, but microscale techniques can help with evidence for ozone and hydroxyl radicals. Here are the videos referred to in the picture.
youtu.be/mlQRDuKm63w 
www.youtube.com/watch?v=U_PA...
www.youtube.com/watch?v=9jNh...
#ITeachchem
bobthechemist.bsky.social
And there was I, thinking you sat down and watched these videos with pen in hand eager for all the information
bobthechemist.bsky.social
if you go to 13 seconds in the video, there is a QR code to a supplier. I hope that helps
bobthechemist.bsky.social
Here is a diffusing precipitate of silver iodide on a thermochromic plastic sheet so that the endothermic dissolving and the exothermic precipitation are seen.
#ITeachchem #RealTimeChem #chatchemistry
@sfed-rsc.bsky.social @beyondbenign.bsky.social,
bsky.app/profile/cerg...
bobthechemist.bsky.social
Watch highly coloured ions MnO₄⁻ & Cu(NH₃)₄²⁺ diffuse in a droplet of water using 2 different paths caused by presence of a magnet during electrolysis. Evidence of charged particles (ions). www.youtube.com/watch?v=qMta... and www.youtube.com/watch?v=w9oM...
#ITeachchem #RealTimeChem #chatchemistry
bobthechemist.bsky.social
Using microscale techniques in school chemistry to show how carbon in CO₂ can be captured and imprisoned, but I had to let it go to show it worked! Video on www.youtube.com/watch?v=Tstu...
bsky.app/profile/did:...
bobthechemist.bsky.social
Watch for the effect of a magnet on the iron/thiocyanate complex. Paramagnetism at work.
www.youtube.com/watch?v=qipp...
#ITeachchem #RealTimeChem #chatchemistry @sfed-rsc.bsky.social
IronIII thiocyanate complex
YouTube video by Bob Worley
www.youtube.com
bobthechemist.bsky.social
Helplines asked #CLEAPSS for an alternative to CuO/H₂SO₄ neutralisation reaction salt making for students to make salts. Not easy, but using ed/ox metal/acid reactions uses the same skills. This is iron(II) sulfate made from staples.
#ITeachchem #RealTimeChem #chatchemistry
0.25 cm³ of 1M copper sulfate is added to the iron staples and 2 cm³ of 1.5M sulfuric acid It is heated for 10 minutes. Can also use steel paper clips. This is the personal spirit burner (ethanol biofuel) hotplate.
Using filter paper in small-scale chem does not work. Filtering the reaction mixture through cotton wool in a Pasteur pipette. Copper particles and bits of iron are separated from the iron(II) sulfate solution.. Heating the filtered solution for 10 minutes on my personal spirit-burner, bio-fuel, hotplate. Then leave to cool. The crystals form slowly, which might take longer than a lesson, but the results are very beautiful.
bobthechemist.bsky.social
Making 1-5% soap solutions in 7:3 propan-2-ol/water. Filtered to get a colourless liquid. Laser light reflection indicates it is colloidal. Is the twinkling effect caused by collisions with water molecules?
#ChatChemistry #ITeachChem @cleapss.bsky.social @cerg.bsky.social
bobthechemist.bsky.social
Evaporation with Thermochromic plastic and 2 kitchen thermometers. Visualise the flow of energy in an open endothermic process at room temperature—an evidence-based small-scale approach using easily available modern materials. #ChatChemistry #ITeachChem @sfed-rsc.bsky.social @cerg.bsky.social
bobthechemist.bsky.social
Students encounter a precipitate every day as they wash with soap & make scum. @cleapss.bsky.social has had this method for 20 years as traditional methods were risky but now introduce a personal hotplate. Students stay still. #ChatChemistry #ITeachStudents @sfed-rsc.bsky.social @cerg.bsky.social
bobthechemist.bsky.social
It works better with bottle top crucible. See Cleapss website. Do a comparison of methods if you want.
bobthechemist.bsky.social
It is all about energy. I think chemists are rather scared of the topic. We invent octet rules to explain and ditch it. We are awe of physics teaching.
bobthechemist.bsky.social
With the correct equipment on silica, you get this for Parker and Octopus Fountain Pen Ink. But inflation means schools are increasingly unable to afford this equipment. The effect is stunning using the solvent mixture butan-1-ol/ethanol/water in the ratio of 3:1:1 and a drop of conc ammonia.
bobthechemist.bsky.social
Many helpline calls regarding aspirin syn come to @cleapss.bsky.social. The cost of the TLC slide is rising more than inflation for schools. Can use iodine to see the chromatogram. The hotplate design comes from teachers in Thailand. Applying #GreenChemistry principles. #ChatChemistry #ITeachChem
bobthechemist.bsky.social
www.youtube.com/watch?v=bj1B... This is copper wire into 0.06 AgNO3 on a plastic surface under a USB microscope. Mobuke phone are good now. ooops!
Silver nitrate reacting with copper wire
YouTube video by Bob Worley
www.youtube.com
bobthechemist.bsky.social
Thanks. You can look at these slides and always contact me #ChatChemistry
bobthechemist.bsky.social
You can use the same approach to make prepene from propan2-ol and alkenes from polythese. See this. www.youtube.com/watch?v=ENyC... where I do a bromine titration of the cracked gases.
Advanced catalytic cracking
YouTube video by Bob Worley
www.youtube.com
bobthechemist.bsky.social
Newish approach to an old experiment as white phosphorus is no longer available. Red phosphorus is. It was the first use of bottle top in school chemistry as an inexpensive alternative to the crucible. @cleapss.bsky.social subscribers see PS67l Burning phosphorus in air
#ChatChemistry #ITeachChem
bobthechemist.bsky.social
We tried this after a Helpline call. "Is this still OK to do". Of course it is. It is also on edu.rsc.org/exhibition-c...
Our catalyst got so hot it vaporised. Clean the copper foil in acid beforehand and the reaction lasts nearly an hour.
#ChatChemistry, #ITeachChem @cleapss.bsky.social
bobthechemist.bsky.social
Rehearse any demos or student practical activitites so you look confident using chemicals and manipulating equipment "on stage". Because that is what you are but remember, you are NOT a children's TV entertainer.
bobthechemist.bsky.social
I hope the new teachers & technicians explore the resources of @CLEAPSS on science.cleapss.org.uk. They can phone or email to get expert advice on any practical activities, safety, storage disposal, recipes, etc. We are not just the safety police! Enter "cracking" into the search engine.
CLEAPSS Science Home
CLEAPSS is a UK based organisation providing services to schools to support practical work in science, design technology and art and design. Most UK schools are already members and so can access all r...
science.cleapss.org.uk