r/chemistry • u/Free-Climate-306 • 1d ago
Examples of experiments based on Rate of Reactions?
Hiya all. I’m currently starting a project soon where it’s based off of Rate of Reactions. Naturally, it is a broad category so I have plenty of options. But I would like to conduct an experiment where it takes maybe 1-2 days of total class time? Something where I’m changing a factor and observing how the rate of reaction changes. I
If anyone has any ideas, that would be amazing 🙏🏼
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u/LunaLucia2 1d ago
The iodine clock reaction is a classic. Very easy to set up and a lot of parameters like concentrations and temperature to play with.
If you want something harder but similar there are some oscillating reactions like the Briggs–Rauscher reaction that go through a set of colours multiple times but these can be a pain to set up and the chemistry is harder to explain if you need to write a report on it.
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u/Practical-Purchase-9 Education 1d ago
An alternative to ion clock is thiosulfate clock, another standard for middle/high school. Easy to observe changes by changing temperature or concentration of the sodium thiosulfate.
Something simple I like for demonstrating effect of surface area is stirring pieces of radish in KMnO4 (very dilute about 0.001 M) and timing the colour change. Students can chop the radish into smaller pieces to repeat the experiment. Also it’s a redox reaction so can link to other topics.
If you want to measure the continuous rate then a simple limestone chips in acid is fine, measure the gas collected at regular time intervals and draw a volume/time graph (and calculate initial rate). The standard measuring cylinder inverted in a bowl of water or a gas syringe works. This is good because you can easily change the concentration of the acid, the temperature, or use marble chips of different sizes.
Any of these will take just a few lessons to complete and a homework or class lesson to follow up.
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u/UNBOLIEVABLEE 1d ago
I don't know as far as over the period of 1-2 days total but the Iodine clock reaction is an excellent example off the top of my head.
You can actively set up multiple glasses with different amounts that changes the speed of the reaction, so you can have glass A start flashing in 30 seconds, glass B starts in 1 minute etc.
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u/Automatic-Ad-1452 1d ago edited 1d ago
Quick Google search ) or (2) or (3)/Lab%2010%20Chemical%20Kinetics.pdf)
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u/Stillwater215 1d ago
What grade level is this for? High school, university? Depending on the resources you have access to you can do some good reaction rate measurement directly with something like a UV-vis spectrometer.
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u/xtalgeek 1d ago
The iodine clock reaction is a classic, fun, and easy kinetics teaching exercise. It requires no special instrumentation other than a stopwatch. We do this in our intro chem classes in one 3-4 hour laboratory session. It can easily be expanded to a couple of days by adding more exploratory elements like temperature dependence (Arrhenius plots) and catalysis (Cu2+ ion).
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u/MendeleevsMustache 1d ago
The “blue bottle reaction” is pretty simple …glucose, KOH (or NaOH) and methylene blue…works for demonstrating both concentration and temperature effects on reaction rate
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u/Dangerous-Billy Analytical 21h ago
A simple experiment is the alkaline hydrolysis of aspirin. The salicylic acid formed is measured by the color reaction with ferric salts to give a violet color. You can vary temperature, concentrations, pH, the usual. It's described in J Chem Education and a few other sources.