27 votes
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How can you build a model of tetrahedral coordination from objects found at home?

Inflate balloons, and tie them «at their stem» like a bouquet of flowers. If you take four of them, not too much inflated, you well demonstrate a situation close to $sp^3$ hybridization. These models ...
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24 votes
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How would I measure the Carbon Dioxide content in Coca Cola over a period of time?

Measure the change in mass over time of the remaining liquid. Though some water will also evaporate, you can control for that by keeping the humidity near 100%. If you have to be precise, collect the ...
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23 votes
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How do I excel in Chemistry?

Chemistry needs a devoting reader. You should try to love chemistry as much as you want! That'll be the ignition for lots of reading and stuff. My pointers: Love chemistry. Learn in an organized ...
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23 votes

Why does bleach feel slippery?

Actually it is saponification. Bleach has alkali added to it, to stabilize it against decomposion to chlorine gas. To wash your hands after contact with bleach was a wise move.
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22 votes
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Counterintuitive Reaction of Aluminium On Steel Balls

This is actually related to the thermite reaction, where the rust on the balls reacts with the pure aluminum in the foil. Here is a pdf detailing the experiment. The activation energy for the ...
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22 votes
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Why do raisins bob up and down in carbonated water?

The raisin has nucleation sites on it that allow bubbles of $\ce{CO2}$ to form. The raisin is light enough to be lifted by the bubbles as they push their way to the surface. As the bubbles are ...
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22 votes
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Why does bleach feel slippery?

Maybe it needs to be clarified that the salt of a strong base and a weak acid can conduct saponification. Therefore the fact that bleach reacts with fatty acids creating soap, does not necessarily ...
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22 votes
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Why doesn't liquid propane in a closed coke bottle burst?

Yes, based on what we can see in the video, your guess appears to be correct: as the propane-filled bottle warmed up, just enough propane evaporated to keep the pressure inside the bottle equal to the ...
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18 votes
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Why does shampoo lather much more the second time it is applied?

Quoting a reddit post from chemist nallen: The short answer is that the dirt and oils from your hair compete for the surfactants making them less available to form lather, which is small bubbles. To ...
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16 votes
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Can I eat the lemons after I have used them as a battery?

In a lemon battery, the zinc from the galvanized nail is giving up electrons and transitioning into an aqueous state: $$\ce{Zn → Zn^2+ + 2e−}$$ While zinc is entering the electrolyte, two ...
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15 votes
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How can I safely handle a concentrated (fuming) nitric acid spill?

Of course, you’ll want to prevent a spillage as well as possible (making sure the bottle doesn’t fall over etc.) but sometimes you just run into bad luck. Let’s hope that your work bench is at least ...
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14 votes

Where do the bubbles in a glass of water come from?

Gases are less soluble in warm water than cold water. The bubbles are likely from dissolved gas coming out of solution as the water warmed. The bubbles are unrelated to self-ionization of water. ...
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14 votes
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What is the purpose of froth in washing clothes?

The froth has little or no effect on the detergent action. In fact detergent manufacturers have to add anti-foaming agents to stop excessive foam generation in automatic washing machines. Froth/foam ...
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14 votes

Improving Elephant Toothpaste experiment

You might try horseradish as a catalyst, rather than yeast. Use the fresh root, not the prepared sauce, and test a few different plants - some are more effective than others. Cosmetic supply stores ...
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14 votes

Are children's sparklers based on a magnesium reaction?

To answer the question, let us understand sparkler chemistry. A sparkler consists of: An oxidizer: potassium nitrate or potassium chlorate. They burn off a mixture and are part of oxidation-reduction ...
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14 votes
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Are children's sparklers based on a magnesium reaction?

What would happen if we threw the sparkler into the water? Would it keep burning under water. Most likely, not. Water is an effective coolant, so a wet sparkler wouldn't be able to propagate a burn ...
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14 votes
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Cleaning with vinegar and sodium bicarbonate

Your intuition is on point. Pretty much all the "lifehacks" praising cleaning abilities of vinegar and sodium bicarbonate are ineffective. The reaction appears vigorous due to the formation ...
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13 votes
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Can I replace potassium nitrate with sodium nitrate in a smoke bomb?

In pyrotechnics, $\ce{NaNO3}$ is normally avoided because it is very hygroscopic. With dried $\ce{NaNO3}$, the effect should be identical. In any case, the usual safety rules apply!
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13 votes
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What is behind of the attraction between a burned matchstick with a magnet?

Some matchstick heads contain iron(III) oxide as a colorant. The yellowish color of the burning match indicates that it has low oxygen, i.e. a reducing flame. It reduces the iron oxide to iron which ...
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13 votes

Melting point of obsidian

Obsidian This is a volcanic glass, formed when rhyolitic lavas cool too quickly for crystals to form. From a chemistry point of view, it's a mixture of silicon dioxide, aluminium oxide, with sodium ,...
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13 votes

How would I measure the Carbon Dioxide content in Coca Cola over a period of time?

Measure concentration in a fixed volume of air Easiest way might be to put it in a sealed impermeable bag or box and measure the CO2 concentration over time. Home hobbyists use something like the MG-...
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13 votes

How can you build a model of tetrahedral coordination from objects found at home?

This one is inspired by ideas from Ed V and Todd Minehardt. The cool thing is that the angles are pretty accurate if the chop sticks reach into the opposite corners of the cube: As a bonus, you can ...
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13 votes

How can I roughly measure a fraction of a gram?

You ask: Can I roughly get the weight that a fraction of a gram without buying a scale just for this crystal making kit? Absolutely. You're in Japan. You have access to Japanese coins which ...
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12 votes
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Gases produced by pyrolysis of cellulose

During pyrolysis, organic compounds are thermally decomposed in the absence of oxygen. The pyrolysis products are classified into categories based on their physical state of existence: char (solid), ...
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12 votes

Why doesn't liquid propane in a closed coke bottle burst?

The person in the video said it was about $\pu{45^oF}$. At this temperature propane has a vapor pressure of about 8 atm, so that is the pressure that built up inside the Coke bottle. Once this ...
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11 votes

Is it possible to extract magnesium from epsom salt?

Supposed you are trying to obtain magnesium metal from Epsom salt, $\ce{MgSO4.7 H2O}$: Is is worth the effort? Magnesium metal in the form of chips (particle size 4-30 mesh) in decent purity (99.98%) ...
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11 votes

How do I excel in Chemistry?

Get a chemistry set and do experiments and have fun. When I was a kid, much younger than you, I asked my mom for 75 cents to buy a chemistry set at a yard sale in our neighborhood, but she wouldn't ...
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11 votes
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A unique demo for singlet oxygen?

Admittedly, I'm having a professional photochemical bias when it comes to the generation of singlet oxygen! A rather safe and simple approach - even in home experiments - is the use of air, sunlight ...
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11 votes
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Cold-sensitive magic pen

The ink you describe is an example of a leuco dye, which are molecules that exist in colored or non-colored states depending on what they're interacting with and under what conditions (temperature, pH,...
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11 votes

What is the simplest way to create a precipitation reaction at home?

Here's one easy way : Make a solution of salt ($\ce{NaCl}$) in water, and another solution of Silver Nitrate ($\ce{AgNO_3}$), which you can buy easily) in water. Upon mixing the two, $\ce{AgCl}$ (...
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