27
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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 ...
- 28.4k
25
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.
- 53.3k
25
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 ...
- 30.5k
25
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Why does my sand dissolve in citric acid?
Your sand dissolves in citric acid because it is carbonate sand.
Not all sand is formed by quartz, even if it is usually implied in context of masonry or fish-keeping. There are sometimes used ...
- 39.4k
24
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 ...
- 944
23
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 ...
- 446
23
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 ...
- 23.9k
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 ...
- 2,168
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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17
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 ...
- 4,312
16
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 ...
- 67.3k
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 ...
- 4,505
15
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 ...
- 30.5k
15
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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 ...
- 21.5k
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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13
votes
Accepted
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 ...
- 7,142
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 ,...
- 231
13
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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
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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 ...
- 39.1k
13
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 ...
- 37.4k
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), ...
- 23.9k
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 ...
- 17.4k
12
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 ...
- 10.6k
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, $\ce{AgCl}$ (...
- 119
11
votes
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Chemical reaction in homemade deodorant
The most likely culprit is something acidic reacting with the baking soda (sodium bicarbonate).
Try mixing separately:
Baking soda and witch hazel
Baking soda and aloe vera gel
My guess is that one ...
- 17.3k
10
votes
How do I control the negative temperature in an experiment?
For temperatures below room temperature cooling baths are used.
These baths consist of a solvent + something that has a low temperature already (ice, dry ice, or liquid nitrogen). A comprehensive list ...
- 17.1k
10
votes
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Producing ketones from secondary alcohols using hydrogen peroxide
I think it is possible to use hydrogen peroxide. This paper discusses it: http://greenchem.uoregon.edu/PDFs/ResourceID88.pdf
Other alternatives:
Pyridinium Chlorochromate (or PCC for short)
Dess-...
- 8,465
9
votes
Separating iron from blood
It is not possible to separate iron from blood without damaging the haemoglobin. Iron is a part of haemoglobin, and if iron is removed, the haemoglobin becomes something else. The blood then becomes ...
- 1,473
9
votes
Accepted
How to extract caffeine from coffee
The popular procedure to experimentally isolate caffeine is sublimation.
Slowly heat a teaspoon of coffee or tea from 150°C to 250°C. Let the sublimated caffeine precipitate at a watch glass cooled ...
- 7,142
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