10 Awesome Chemistry Experiments for High School Students

The subject of chemistry is one subject that sends shivers down the spines of students, and sometimes even parents(maybe when they remember their own high school days). Yet chemistry is everywhere, right from the food we eat to the pharmaceuticals we use and the cosmetics we are so fond of.

Therefore, performing certain fun-filled experiments with our high schoolers is a sure-shot way to get the fear of chemistry out of their minds. Where fear stops, curiosity is aroused. Hence, let the learning begin.

1. Mystical Cloud

To create the mystical cloud, perform the following steps:

  1. In an opaque bottle, mix 30% hydrogen peroxide. 
  2. Lower a tea bag containing potassium iodide into the bottle. 
  3. The exothermic reaction between the hydrogen peroxide and potassium iodide will rapidly release oxygen gas, forming a large, mystical-looking cloud in the bottle.

Explanation:

This experiment demonstrates the chemical reaction that produces the cloud, as well as the concept of gas formation. The opaque bottle creates a dramatic visual effect, making the cloud appear “mystical.” 

This mystical cloud experiment is sure to catch the eye, as well as the young minds of our high schoolers and get them started on the chemistry journey!

2. Dancing spaghetti experiment

Here is how to do the dancing spaghetti chemistry experiment:

  1. Pour 1 cup of water into a tall clear glass and add 2 teaspoons of baking soda. Stir until the baking soda is fully dissolved.
  2. Break uncooked spaghetti noodles into 1-inch pieces and place about 6 pieces into the glass. The spaghetti will sink to the bottom.
  3. Add 5 teaspoons of vinegar to the glass. Observe as the spaghetti pieces start to rise up and “dance” around due to the chemical reaction between the baking soda and vinegar producing carbon dioxide gas bubbles.
  4. As the spaghetti dance slows down, add a bit more vinegar to keep the reaction going and the spaghetti dancing.

Explanation:

The spaghetti dances because the carbon dioxide bubbles attach to the rough surface of the noodles, decreasing their density so they float up. When the bubbles pop at the surface, the spaghetti sinks again until more bubbles form. This demonstrates the principles of buoyancy and chemical reactions.

This dancing spaghetti experiment will help the student understand the magic of chemistry in lifting the spirits of scientific inquiry.

3. Bouncy balls to explore polymer properties

Steps to make the bouncy balls:

  1. Mix 3 level spoonfuls of Elmer’s glue (which contains the polymer polyvinyl acetate), with 5 mL of water and 1 level spoonful of borax powder(which forms cross-links between the polymer chains). Allow to interact for 10-15 seconds before stirring.
  2. Once the mixture becomes difficult to stir, remove it from the container and knead it with your hands. The ball will start to be sticky and messy but will solidify as you knead it.
  3. Record observations about the ball’s appearance, stretchiness, and bounciness.
  4. Try varying the amounts of glue, water, and borax, or adding cornstarch to see how it affects the final bouncy ball properties.

Explanation:

This experiment allows students to explore how changing the polymer composition and cross-linking affects the physical properties of the resulting material. It’s a great hands-on way to learn about the versatile nature of polymers.

The bouncy balls are an exciting and fun-filled experiment to understand everyday applications of chemistry.

4. Colourful flames experiment

Here are some ways to create colorful flames by adding different chemicals:

  1. Sprinkle salts like sodium chloride (table salt), copper(II) chloride, strontium chloride, or barium nitrate into an alcohol flame to produce yellow, green, red, or blue colors. The heat excites the atoms in the salts, causing them to emit characteristic colored light as the electrons return to their ground state.
  2. Soak wood chips or sawdust in solutions of metal salts like copper sulfate (blue-green), strontium chloride (red), lithium chloride (pink), or boric acid (green). Allow to dry, then toss the treated chips onto a campfire to produce colored flames.
  3. Embed metal salts into paraffin wax to make “colored fire wax cakes”. Melt wax in a double boiler, mix in the desired salts, pour into cupcake liners, and let harden. Toss the wax cakes onto a fire for long-lasting colored flames.

Explanation:

The colors produced depend on the specific metal ions present. Sodium gives yellow, copper gives blue-green, strontium gives red, and barium gives green flames. The colors are produced because the metal ions in the salts emit light at specific wavelengths when heated in the flame. This is the same principle used to create colored fireworks

Creating colorful flames by adding different chemicals to a flame is a beautiful rainbow experiment to spark an igniting and everlasting flame of interest for chemistry.

5. Extracting anthocyanin pigment from red cabbage to create a natural pH indicator

To extract anthocyanin pigment from red cabbage and create a natural pH indicator, follow these steps:

  1. Chop red cabbage leaves into fine pieces to allow the water to extract the anthocyanins.
  2. Add the chopped cabbage to a pot and cover with distilled water. Bring the mixture to a boil, then simmer for 25 minutes, stirring occasionally
  3. Filter the solution through a coffee filter or strainer to remove the cabbage pieces, leaving just the anthocyanin-infused water
  4. (Optional) Boil off 20-50% of the solution to concentrate the anthocyanins for more vibrant colors.5
  5. Use the anthocyanin solution to test the pH of various household substances:
  6. Acids like lemon juice, vinegar, and grapefruit juice will turn the solution red.
  7. Neutral substances like water will keep the solution blue or purple
  8. Bases like baking soda and ammonia will turn the solution green or yellow.

Explanation:

The anthocyanin pigments change color due to a chemical reaction that occurs at different pH levels. This natural pH indicator provides a fun way to explore acids, bases, and neutrals.

This red cabbage experiment thus is an exciting experiment to familiarise the students with the entire spectrum of pH with its acids, bases, and neutrals!

6. Elephant toothpaste experiment

The key steps to form the elephant toothpaste foam are:

  1. Mix 1/2 cup of 3% hydrogen peroxide with a squirt of dish soap in a plastic bottle.
  2. Add a few drops of food coloring if desired.
  3. In a separate cup, mix 1 tablespoon of yeast with 3 tablespoons of warm water. Stir for 30 seconds.
  4. Quickly pour the yeast mixture into the bottle and watch the foamy reaction erupt.

Explanation:

The reaction occurs because the catalyst (yeast or potassium iodide) speeds up the decomposition of the hydrogen peroxide into water and oxygen gas. The dish soap traps the oxygen bubbles, creating a dramatic foaming effect. The reaction continues as long as there is hydrogen peroxide and a catalyst remaining.

Thus, this exothermic reaction creates the elephant toothpaste, as well as exponentially engages the curiosity of the students performing the experiment.

7. Chromatography with coffee filters

Chromatography with coffee filters is a simple science experiment that demonstrates the separation of colors in ink or dye. To do this experiment:

  1. Draw a circle with a washable marker on a coffee filter, leaving the center blank. Fold the filter into a triangle. 
  2. Suspend the folded filter in a cup of water, making sure only the tip touches the water. The water will travel up the filter, separating the colors in the marker. 
  3. After 15-30 minutes, the colors will separate and become visible on the filter. Common results show blue, green, and red/pink colors emerging from the original black marker. 

Explanation:

This experiment works because of capillary action and chromatography – the water carries the water-soluble dye molecules at different rates through the filter material. However, it is important to remember that Permanent markers do not work as well since their dyes are not water-soluble. 

The separation of colors provides a spectacular result that will surely capture the imagination of young minds!

8. Lava lamp experiment

Steps to create the spectacular lava lamp:

  1. Fill a clear plastic bottle about 1/4 full with water. Pour vegetable oil into the bottle until it is almost full, then wait a couple of minutes for the oil and water to separate.
  2. Add a few drops of food coloring, which will sink through the oil, and mix with the water
  3. Break an Alka-Seltzer tablet into pieces and drop them into the bottle. The tablet will sink to the bottom, start dissolving, and release carbon dioxide gas bubbles.
  4. The bubbles will attach to the colored water blobs, making them float to the top. When the bubbles pop, the colored water will sink back down.

Explanation:

The lava lamp works because oil is less dense than water, so it floats on top. The food coloring has the same density as water, so it sinks through the oil. The gas bubbles from the Alka-Seltzer are lighter than water, so they float up, bringing the colored water with them

Fun tip: To keep the lava lamp going, just drop in another piece of Alka-Seltzer tablet when the bubbling slows down. Your evergreen lava lamp may just spark a permanent love for all chemicals and chemistry!

9. Magic milk experiment

The magic milk experiment demonstrates how soap interacts with the fats and proteins in milk:

  1. The magic milk experiment involves pouring milk into a shallow dish and then adding food coloring. 
  2. It is followed by touching a cotton swab dipped in dish soap to the surface of the milk. This causes the food coloring to swirl and dance around, creating a colorful “fireworks” effect.

Explanation:

The reason this happens is that the soap molecules have a hydrophilic (water-loving) end and a hydrophobic (water-fearing) end. When the soap touches the milk, the hydrophobic ends attach to the fat molecules, causing them to move around rapidly. The food coloring gets swept up in this motion, resulting in a colorful display. 

Another way to get even more creative with the experiment is to try it with different types of milk to see how the fat content affects the results. The more fat in the milk, the more dramatic the color display will be, and faster your student will be fascinated with chemistry!

10. Ammonia fountain experiment

The ammonia fountain experiment demonstrates the high solubility of ammonia gas in water due to hydrogen bonding. Here’s how it works:

  1. A flask is filled with dry ammonia gas by heating a mixture of calcium hydroxide and ammonium chloride.
  2. Water is injected into the flask through a syringe, causing the ammonia gas to rapidly dissolve. This creates a partial vacuum inside the flask.
  3. The external atmospheric pressure forces water up a tube and out through a jet, creating a fountain effect. The ammonia solution is alkaline, so adding a pH indicator like phenolphthalein turns it pink.
  4. As more ammonia dissolves, the pressure inside the flask drops further, causing the fountain to continue for several minutes.

Explanation:

This experiment illustrates the concepts of solubility, gas laws, and acid-base chemistry at an introductory level. It can also be done with other highly soluble gases like hydrogen chloride.

The ammonia fountain experiment will surely skyrocket your high schooler’s interest in chemistry experiments and the various explanations of the world it opens to them.

Chemistry is often referred to as the “central science” because it connects various fields, including physics, biology, and environmental sciences. Thus, it is absolutely imperative that students not view it as a textbook roadblock on the way to graduation. Rather, it should be seen as an exciting hiking trip that will become more adventurous while passing each milestone. 

The same holds true for physics. And we can prove to you that physics can be fun too with these physics experiments for high school students!

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