Candle Science Magic Trick
You know you can put out a candle flame by pouring water on it. In this science magic trick or demonstration, the candle will go out when you pour 'air' onto it.
Candle Science Magic Trick Materials
- a lit candle
- a transparent glass (so people can see what is inside the glass)
- baking soda (sodium bicarbonate)
- vinegar (weak acetic acid )
Set up the Magic Trick
In the glass, mix together a little baking soda and vinegar. How to Blow Out the Candle with Chemistry
Simply pour the gas from the glass onto the candle. The flame will be extinguished. Another way to perform this trick is to pour the gas that you just made into an empty glass and then pour the apparently empty glass over the candle flame.
How the Candle Trick Works
When you mix baking soda and vinegar together, you produce carbon dioxide. The carbon dioxide is heavier than air, so it will sit in the bottom of the glass. When you pour the gas from glass onto the candle, you are pouring out the carbon dioxide, which will sink and replace the (oxygen-containing) air surrounding the candle with carbon dioxide. This suffocates the flame and it goes out.
Hand held Fireballs
Fire is made up of light and heated gases from combustion. You can control the temperature of fire by selecting a fuel that burns with a cool flame. If you pour the fuel onto a substance that won't burn, you can make a fireball that you can hold in your hand or juggle. Here are written instructions for making your own hand held fireballs. There is also a step-by-step video tutorial of this fire project if you would like see what to expect.
Materials Needed to Make Fireballs
- 2" x 5" strip of cotton cloth (like from a t-shirt).
- 100% cotton thread.
- needle.
- naphtha lighter fluid (e.g., Ronsonol™).
- match or lighter.
How to Make a Fireball Thread the needle with cotton thread.
Tightly roll the cotton strip into a ball.
Pierce the ball with the needle and wrap the ball with the thread. End by running the needle through the ball one more time and break off the thread.
Soak the ball with lighter fluid. Don't soak your hands.
Don't ignite the the fireball while you are holding it. Set the ball on a fire-proof surface. I used a frying pan from my kitchen.
If you want to hold the fireball, my recommendation is to pick it up with tongs and carefully/slowly set it on your hand. That way you'll be able to tell if you can take the heat or not. Once you gain some confidence, you can pick the fireball up using your fingers.
Colored Fire Spray Bottles
n the pilot episode of "Breaking Bad", chemistry teacher Walt White performs a demonstration in which he changes the color of a Bunsen burner flame by spraying the flame with chemicals. You can perform the colored fire demonstration yourself. All you need are some common chemicals, alcohol, and spray bottles. Here is a list of metal salts you can use to (safely) color fire. The chemicals have low toxicity and any smoke produced won't be any better/worse for you than normal wood smoke:
Colored Fire Chemicals :
dark red = lithium chloride
red = strontium chloride (found in emergency flares)
orange = calcium chloride (a bleaching powder)
yellow = sodium chloride (table salt) or sodium carbonate
yellowish green = borax (sodium borate, a common insecticide and cleaning agent)
green = copper sulfate (found in some pool and aquarium chemicals)
blue = copper chloride (lab chemical, but other copper compounds found in algicides and fungicides may work)
violet = 3 parts potassium sulfate, 1 part potassium nitrate (saltpeter)
purple = potassium chloride (sometimes sold as a 'lite' salt)
white = magnesium sulfate (Epsom salts)
Prepare the Flame Colorants:
If you were just coloring a campfire or other wood fire, you could simply sprinkle the dry metal salts onto the fire. Copper chloride is especially nice for this since the sodium that is naturally present in wood causes this chemical to produce a mix of blue, green, and yellow flames. However, for the gas flame in a burner, you need the salts dissolved in a flammable liquid. The obvious choice here is alcohol. Common alcohols found around the home could include rubbing alcohol (isopropyl alcohol) or ethanol (e.g., in vodka). In some cases, the metal salts will first need to be dissolved in a small volume of water and then mixed with alcohol so that they can be spray onto a flame. Some salts may not dissolve, so what you can do is grind them into a fine powder and suspend them in liquid.
Invisible Inks
This is photo of invisible ink This
smiley face was made with invisible ink.
The face became visible when the paper was heated.
Sometimes people tell me they can't do any science projects because they don't have any chemicals. There are some activities that don't require any chemicals you don't already have. A great example is invisible ink.
Invisible ink is any substance that you can use to write a message that is invisible until the ink is revealed. You use the ink by writing your message with it using a cotton swab, dampened finger, fountain pen, or toothpick. Let the message dry. You may want to write a normal message on the paper so that it doesn't appear to be blank and meaningless. If you write a cover message, use a ballpoint pen, pencil, or crayon, since fountain pen ink could run into your invisible ink. Avoid using lined paper to write your invisible message, for the same reason.
How you reveal the message depends on the ink you used. Most invisible inks are made visible by heating the paper. Ironing the paper or holding it over a 100-watt bulb are easy ways to reveal these types of messages. Some messages are developed by spraying or wiping the paper with a second chemical. Other messages are revealed by shining an ultraviolet light on the paper.
Make Invisible Ink
Anyone can write an invisible message, assuming you have paper, because body fluids can be used as invisible ink. If you don't feel like collecting urine, here are some alternatives:
Heat-Activated Invisible Inks
Iron the paper, set it on a radiator, place it in an oven (set lower than 450° F), hold it up to a hot light bulb.
any acidic fruit juice (e.g., lemon, apple, or orange juice)
onion juice
baking soda (sodium bicarbonate)
vinegar
white wine
dilute cola
diluted honey
milk
soapy water
sucrose (table sugar) solution
urine
Inks Developed by Chemical Reactions
These inks are sneakier, because you have to know how to reveal them. Most of them work using pH indicators, so when it doubt, paint or spray a suspected message with a base (like sodium carbonate solution) or an acid (like lemon juice). Some of these inks will reveal their message when heated (e.g., vinegar). phenolphthalein (pH indicator), developed by ammonia fumes or sodium carbonate (or another base)
thymolphthalein, developed by ammonia fumes or sodium carbonate (or another base)
vinegar or dilute acetic acid, developed by red cabbage water
ammonia, developed by red cabbage water
sodium bicarbonate (baking soda), developed by grape juice
sodium chloride (table salt), developed by silver nitrate
copper sulfate, developed by sodium iodide, sodium carbonate, potassium ferricyanide, or ammonium hydroxide
lead(II) nitrate, developed by sodium iodide
iron sulfate, developed by sodium carbonate, sodium sulfide, or potassium ferricyanide
cobalt chloride, developed by potassium ferricyanide
starch (e.g., corn starch or potato starch), developed by iodine solution
lemon juice, developed by iodine solution
phenolphthalein (pH indicator), developed by ammonia fumes or sodium carbonate (or another base)
thymolphthalein, developed by ammonia fumes or sodium carbonate (or another base)
vinegar or dilute acetic acid, developed by red cabbage water
ammonia, developed by red cabbage water
sodium bicarbonate (baking soda), developed by grape juice
sodium chloride (table salt), developed by silver nitrate
copper sulfate, developed by sodium iodide, sodium carbonate, potassium ferricyanide, or ammonium hydroxide
lead(II) nitrate, developed by sodium iodide
iron sulfate, developed by sodium carbonate, sodium sulfide, or potassium ferricyanide
cobalt chloride, developed by potassium ferricyanide
starch (e.g., corn starch or potato starch), developed by iodine solution
lemon juice, developed by iodine solution
Inks Developed by Ultraviolet Light (Black Light)
Most of the inks that become visible when you shine a black light on them also would become visible if you heated the paper. Glow-in-the-dark stuff is still cool. Here are some chemicals to try: dilute laundry detergent (the bluing agent glows)
body fluids
tonic water (quinine glows)
vitamin B-12 dissolved in vinegar
dilute laundry detergent (the bluing agent glows)
body fluids
tonic water (quinine glows)
vitamin B-12 dissolved in vinegar
Any chemical that weakens the structure of paper can be used as an invisible ink, so you might find it fun to discover other inks around your home or lab.
