Introduction
Yes — you probably know a few dramatic chemistry demos, but this quiz will show how deep your knowledge of weird chemical reactions really goes. From color-changing solutions to fizzy surprises, some reactions are pure theatre and others hide clever science.
About the Quiz
This quiz tests your recognition of famous and strange reactions: what causes the color shifts, which gases are produced, and which classic demonstrations are mostly just chemistry showmanship. Expect a mix of safe everyday chemistry and curious lab phenomena.
Instructions
- Answer each multiple-choice question. There are 10 questions total.
- Try to picture the reaction — many hints are visual or sensory.
- Click through explanations after each answer to learn a quick fun fact.
Take your time and enjoy the tiny shocks and colors. I love how a few drops can make a beaker look like a miniature sunset — and you will, too, once you know the why.
Weird Chemical Reactions Quiz
Test your knowledge of strange, colorful, and surprising chemical reactions — from fizzing volcanoes to color-changing solutions.
The popular 'elephant's toothpaste' demo produces a huge foamy column. What chemical process mainly creates that foam?
Elephant’s toothpaste comes from hydrogen peroxide breaking down into water and oxygen very quickly when a catalyst is added; the escaping oxygen gets trapped in soap to make foam.
Which reaction explains why red cabbage juice changes color when you add lemon juice or baking soda?
Anthocyanins in red cabbage change structure with pH, shifting which wavelengths they absorb — acids make it redder, bases turn it green or blue.
Which of these dangerous mixes is known for producing highly unstable and explosive compounds and should never be attempted?
Acetone plus hydrogen peroxide (especially with an acid) can form organic peroxides — shock-sensitive and volatile. It’s hazardous and not a DIY experiment.
Which phenomenon causes a solution of potassium permanganate to turn colorless during reduction reactions in some demonstrations?
Permanganate (purple) is reduced to Mn2+, which is pale or nearly colorless in solution — that change powers several classic ‘disappearing color’ demos.
What gas is usually responsible for the fizzy eruption in the classic 'baking soda + vinegar' volcano?
When vinegar (acetic acid) reacts with baking soda (sodium bicarbonate), carbon dioxide gas is produced — it’s the CO2 bubbles that make the fizz and foam.
Blue fire or flames often seen in lab demos indicate what about the combustion?
Blue flames usually mean hotter, cleaner combustion where molecular and atomic emissions occur at shorter (bluer) wavelengths; soot-glowing yellow flames are cooler and incomplete.
The 'clock reaction' that suddenly changes color after a delay relies on what key idea?
Clock reactions depend on reaction networks and intermediates: once certain reactant ratios shift, a rapid change (like a color jump) happens — it’s kinetic control, not evaporation or magnetism.
Which metal reacts vigorously with water, sometimes producing flames and hydrogen gas, and is famous in demonstrations?
Alkali metals like sodium react with water to release hydrogen gas and heat — the hydrogen can ignite, which is why these demos are dramatic and must be handled by professionals.
What causes 'thermite' reactions to produce molten iron and intense light?
Thermite mixes aluminum powder with iron oxide; aluminum is oxidized while iron oxide is reduced, releasing a huge amount of heat that melts iron.
Why do some chemical reactions appear 'cold' to the touch even though they release energy (like some rapid oxidations)?
Sometimes the energy is released as light (photons) or used to do work (gas expansion) so less sensible heat reaches your skin — plus a lab setup or vessel can disperse heat quickly.