Fire Extinguisher – Home Experiment

You will need

  • Candle
  • 2 Glasses (need to be higher than the candle)
  • Vinegar
  • Baking soda
  • Teaspoon
  • Match to light the candle

What to do

  1. Put the candle in one glass and light it.
  2. In the other glass, place 1 teaspoon of baking soda.
  3. Pour vinegar over the baking soda until it is just covered.
  4. Wait for the baking soda and vinegar finish frothing.
  5. Take the glass with the baking soda and vinegar and slowly tilt it over the glass with the burning candle. Be careful to not to let the vinegar drip over into the glass with the candle.
  6. Observe what happens to the candle.

Background

When vinegar reacts with baking soda, the gas carbon dioxide is formed. Carbon dioxide is heavier than air and stays in the glass. As you tilt the glass with carbon dioxide over the candle, it replaces the air with the oxygen needed for the flame. The non-flammable carbon dioxide gas smothers the flame.

Vinegar and Baking Soda Bomb

Background

Vinegar is an acid and reacts with baking soda to form salt, water and carbon dioxide gas. The extremely fast formation of carbon dioxide gas will cause your zipper back bomb to explode.

You will need

  • Plastic zipper bag
  • Vinegar (any kind will do, but you will need quite a lot of it)
  • Baking soda
  • Cup, glass or mug
  • Table spoon

What to do

  1. Go outside to do this experiment.
  2. Check your zipper bag to make sure that it does NOT have any holes or rips before the experiment.
  3. Fill your glass or mug completely with vinegar
  4. Pour the vinegar from your glass or mug into the plastic zipper bag.
  5. Place the zipper bag on the ground.
  6. Add one heaped table spoon of baking soda and quickly close the bag.
  7. Quickly step away from the zipper bag and watch what happens.

You can watch this experiment here:

Match Boats

You will need

  • 1 Bowl
  • Washing-up liquid
  • 1 Match
  • Water
  • 1 Knife

What to do

  1. Fill the bowl with water.
  2. Split the match slightly at its lower end using the knife.
  3. Smear the split end with some washing-up liquid.
  4. Place the match in the water and watch what happens.
  5. The soap will dissolve slowly in the water which causes a backwards movement of the water molecules. This lets the boat move forward.
  6. If you want to repeat the experiment, change the water in the bowl and use a new match.

You can also watch this experiment here:

Optical Illusion – Home Experiment

Background

Our eyes can only see a certain amount of pictures per second. They are actually quite slow. This is why we cannot see objects that are moving extremely fast. In this experiment we are going to use the slowness of our eyes.

You will need

  • Paper
  • Pencil
  • Pens or colouring pencils to draw a picture
  • Tape
  • Scissors

What to do

  1. From the paper cut two pieces with the same shape and size.
  2. Draw two different pictures on the two pieces of paper that can also go together, for example a rabbit on one piece of paper and grass on the other. You could also do a bowl of water on one piece and fish on the other one. Or a bird on one piece and a tree on the other one for the bird to sit on.
  3. Tape both pieces of paper on either side at the end of a pencil. The pictures need to face outside.
  4. Now rub the pencils between your hands as if it was a stick that you want to light a fire with.
  5. Look at the pictures.
  6. You will see both pictures combined together, for example the rabbit sitting on the grass or the fish in the bowl.

The reason this works is that our eyes are too slow to follow the fast movement of the pictures and can only see a limited amount of pictures per second.

You can also watch this experiment as a video:

M&M Diffusion Experiment

Background

Diffusion is the movement of particles from a place of high concentration to a place of low concentration. We can also say that particles move from where there are lots of particles to where there are less particles.

In this experiment we are going to look at the diffusion of colour particles. You will observe the colour moving away from the sweets where lots of colour particles are found to places with less colour particles in the middle of the plate.

You will need

  • M&Ms or Smarties
  • Plate
  • Water

What to do

  1. Once you start this experiment, you cannot move it. So, make sure you choose a good spot to start.
  2. Pour the bag of M&Ms or Smarties onto your plate.
  3. Remove the sweets that landed in the middle of your plate.
  4. Place the remaining sweets in a circle around the outside of your plate.
  5. Remove any remaining M&Ms or Smarties that do not fit in the circle.
  6. Slowly add water to your plate. It needs to reach the M&Ms, but they should not float. From now on you cannot move the experiment.
  7. Observe what happens to the colour of the sweets.

You can also watch this experiment on YouTube:

Static Electricity at Home

Background

When a balloon is rubbed against hair, a towel or a jumper, it gains more electrons which have a negative charge. This gives the balloon an overall negative charge. Objects with a positive charge or no overall charge like a tin can will now be attracted (= be drawn) to the balloon. We call this “static electricity”.

You will need

  • Balloon
  • Towel, jumper or your hair
  • Empty soda can
  • Water tap
  • A smooth surface, e.g. a table

What to do

  1. Blow up the balloon.
  2. Put the empty soda can on its side on a smooth surface.
  3. Rub the balloon on a towel, jumper or your hair to create static electricity.
  4. Hold the balloon close to the side of the soda can, but do not let them touch.
  5. Slowly move the balloon away from the soda can along the surface.
  6. Observe what happens.
  7. Rub the balloon again on a towel, jumper or your hair.
  8. Open the water tap, so that only very little water is running. It should be almost dripping.
  9. Hold the balloon close to the water, but do not let the balloon touch the water.
  10. Observe what happens.

You can also watch this experiment here:

Rainbow in a Glass

Background

Density tells you how heavy a certain volume of a substance is. It decides which materials can float on water and which sink. For example, a rock will sink because its density is higher that the density of water. However, wood floats because its density is lower than that of water.

The same is true for liquids. Liquids with high densities sink, while liquids with lower densities float. We are going to use this to make a rainbow in a glass. Chocolate sauce has a highest density of the four liquids and will stay at the bottom. However, water has the lowest density and will, therefore, float on top.

You will need

  • 1 Glass
  • 1 Spoon
  • Chocolate sauce
  • Honey
  • Washing up liquid
  • Water
  • Red food colouring

What to do

  1. Start by pouring chocolate sauce into your glass until it is one quarter full.
  2. Use the spoon to carefully add the honey until your glass is half full. Do NOT stir!
  3. Now add the washing up liquid slowly and until your glass is three quarters full.
  4. In a separate glass mix water with red food colouring.
  5. Carefully add the water dropwise until your glass is full. Do NOT stir!

You can watch this experiment as a YouTube video:

 

Lemon Volcano

You will need

  • 1 plate or tray
  • 1 lemon
  • 1 cutting knife (to cut the lemon)
  • 1 butter knife
  • Baking soda
  • 1 table spoon
  • Food colouring (1 to 4 colours of your choice)

What to do

  1. Cut your lemon in half. Then cut of a bit at the bottom, so that the lemon can now stand up.
  2. Place the lemon on the plate or tray with the wide side facing up.
  3. Use the butter knife to poke holes in the flesh.
  4. Add 8 to 10 drops of food colouring spread out over the lemon.
  5. Add 1 heaped table spoon of baking soda.
  6. Poke with the butter knife to mix the baking soda with the lemon juice.

The acid in the lemon reacts with the baking soda to form salt, water and carbon dioxide gas. The carbon dioxide gas will cause fizzing. We also call this effervescence.

You can watch this experiment on YouTube:

Coke and Mentos Fountain

Background

Catalysts are substances that speed up chemical reactions. However, they do not directly take part in the reaction and are not used up themselves.

Cars contain catalysts in catalytic converters that split toxic substances released by the car’s engine into less harmful ones.

The gas bubbles inside coke are the result of a chemical reaction where carbonic acid decomposes to water and carbon dioxide gas. The bubbles you feel when drinking coke are carbon dioxide. The word equation for this reaction is:

Carbonic acid → Water + Carbon dioxide

Carbonic acid is the reactant. Water and carbon dioxide are the products.

Mentos can act as a catalyst and increase the speed of carbon dioxide production. This causes the foaming you can see when adding Mentos to coke. The scientific word for bubbles, fizzing or foaming is effervescence.

You will need:

  • 1 bottle with coke or diet coke (Normal coke and diet coke both work, but diet coke is less sticky and easier to clean up afterwards.)
  • 1 pack of Mentos

What to do:

  1. Go outside to do this experiment.
  2. Put the coke bottle on the floor and remove the lid.
  3. Put about 5 pieces of Mentos inside at the same time.
  4. Step back and watch.
  5. You should see a lot of foaming due to the increased carbon dioxide production.

Questions

  1. What is meant by a “catalyst”?
  2. What is the catalyst in this reaction?
  3. Is the Mentos used up in this reaction or not? Why?
  4. What is meant by the “reactant” in a reaction? What is the reactant in this reaction?
  5. What is meant by the “product” in a reaction? What are the products in this reaction?
  6. Where are catalysts used in our everyday lives?
  7. What is meant by “effervescence”?

You can watch this experiment on YouTube:

Reacting Vinegar and Baking Soda

You will need:

  • Baking soda (= alkali)
  • Vinegar (= acid)
  • 1 empty, clean bottle
  • 1 spoon
  • 1 balloon

What to do:

  1. Fill the bottle about one third with vinegar (your acid).
  2. Use the spoon to fill the balloon with baking soda (your alkali). You might need another person to help you and hold the balloon open.
  3. Put the opening of the balloon over the opening of the bottle. (See image above.)
  4. Now tip the baking soda from the balloon into the bottle.
  5. A neutralization reaction will take place where the acid and alkali react to form the products salt, water and carbon dioxide. All three products are neutral substances. Observe what happens.

Questions

  1. Which signs do you see that tell you a chemical reaction is happening?
  2. What happens generally in a neutralization reaction?
  3. Which two products are formed in the neutralization reaction?
  4. Which colour would the following have when adding universal indicator?                   A) Vinegar          B) Baking soda       C) The products after the reaction

You can watch this experiment on YouTube: