The image that chemistry conjures up is one of a scientist with messy hair handling bubbling, frothing liquids. Reality however, is a lot more drearier. In school, chemistry involves more reading and writing than playing havoc with chemicals in a lab.
Here are 5 chemistry experiments you can carry out in class, to put the fun back in Chemistry class!
1. A Home Made Lava Lamp Lava lamps are decorative novelty lamps which have globs of wax moving up and down hypnotically within the jar as they are heated by an incandescent bulb placed at the bottom of the lamp. While, this is a novelty decorative item, you could combine the making of lava lamps with a class on miscible and im-miscible liquids and chemical reactions.
Materials Required: Water, a clear plastic bottle, vegetable oil, food colouring, any tablet that fizzes (like antacids)
- Pour water into the bottle till it is one quarter full.
- Then pour vegetable oil into the bottle until it is nearly full.
- Oil and water won’t mix. So wait until the oil and water separate.
- Add a few drops of food coloring to the bottle.
- Let the food coloring settle into the bottle and watch as it mixes with the oil and water.
- Once, the food coloring settles, drop a portion of an antacid into the bottle and watch as the antacid, which contains sodium bicarbonate and citric acid, reacts with water to form sodium citrate and carbon dioxide gas.
- Miscible and Immiscible Liquids
2. Invisible Ink!
Just thinking of invisible ink makes one think of mystery, crime and adventure. However, if you know the science behind it, the secret of invisible ink is not so secret anymore.
Materials Required: Half a lemon, water, spoon and bowl, cotton buds, white paper, a light source
- Squeeze some lemon juice into the bowl and add a few drops of water to it and mix the two with the spoon.
- Dip the cotton bud into the mixture and write a message on the paper.
- Wait for the writing to dry until it becomes completely invisible.
- Wow your class by heating the paper by holding it close to a light bulb or a light source! The message will appear across at the paper as a dull brown.
- Organic Acids
- Oxidation Reactions
3. The Diet Coke and Mentos Explosion
The Diet Coke and Mentos Explosion is a famous experiment that was first captured on video in 2005 by Steve Spangler. It involves dropping a Mentos candy into a bottle of diet coke and then watching a geyser (10 feet high or more) of carbonated soft drink erupting from the bottle.
This experiment, while very exciting and fun to watch, is going to be a messy one.
CAUTION – For best results it should probably be carried out on the games field or in an unused classroom. If you are going to carry it out in a classroom, then it’s probably good to keep a mop and a wash cloth ready nearby.
Materials Required: A two-litre bottle of Diet Coke, half a pack of Mentos, a funnel
- Ask your class to stand a distance away and make sure you yourself have enough leeway to run.
- Stand the Diet Coke bottle upright in an open space, with the lid unscrewed.
- Place the funnel inside the bottle.
- The mouth of the bottle might be too small for the Mentos tablet to go down properly. If you can, break the Mentos tablets down into several small pieces.
- Now for the fun part where you have to drop the pieces of candy down the funnel and then take off like a rocket yourself.
Well, there is no set theory on why this happens. One of the most commonly accepted theories is that carbonated soft drinks have a lot of carbon dioxide in them just waiting to escape. When a Mentos candy is dropped into it, it breaks the surface tension of the coke and because the Mentos candy has tiny dimples on its surface, a huge number of bubbles are able to form because there is an increase in surface area and that is why instead of the coke just spilling out, what you get is an impressive frothy fountain!
4. Giant Bubbles Made of Dry Ice
Credit: mrbrunnerutah @YouTube
This fascinating experiment (which child is not excited by giant soap bubbles?) could be clubbed with a class on transitions of matter.
Materials Required: Water, a large bowl with an outward facing rim, a mixture of dish-washing liquid and water to create a soapy mixture, a long strip of cloth, dry ice.
CAUTION – Dry ice has the potential to dry out skin quite badly. Therefore, wear gloves when you are handling dry ice.
- In a bowl, add some water and add dry ice to the water. The dry ice will begin to dissipate in the form of smoke.
- Take the strip of cloth and soak it in the soapy mixture and run it around the rim of the bowl before holding both the ends of the cloth and dragging it across the bowl
- Now watch the bubble grow!
- Phases of Matter
5. Crazy Putty
Putty is a plastic material which is similar to clay or dough in texture, except it is used in construction and repair work and not as a children’s toy. Here is how you can make a variation for children to play with, which children can bend and squish as they like and even bounce off the floor!
- 2 Containers (with one being smaller than the other, preferably canisters which hold photographic film)
- Food Coloring
- Carpenter’s Glue ( Ask for Fevicol SH in stationery shops)
- 1 tablespoon of Borax
- Add the borax powder to one cup of water to create a solution and keep it aside.
- Pour the fevicol into the bottom of the big container.
- Add a few drops of food colouring and water as well and stir.
- Add a few drops of borax solution to the mixture, according to the proportion of the mixture.
- Stir the mixture once more and pour it into the smaller container.
- By the now, the mixture should begun bonding together and become squishy putty.
- Chemical Reactions
Are there any fun experiments that you know of or have carried out in your class and by extension impressed your students? Let us know of them in the comments below!