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:

 

Disappearing Egg Shell

Background

In this experiment you will use vinegar to dissolve the shell of a raw egg. Vinegar is an acid and egg shells are made from calcium carbonate. Acids react with metal carbonates like calcium carbonate to form salt, water and carbon dioxide gas. The metal carbonate is dissolved in the process. You can find the word equation below.

Acid + Metal carbonate → Salt + Water + Carbon dioxide

You will be able to observe gas bubbles because carbon dioxide gas is formed. We also call this “effervescence”. The egg shell will dissolve leaving behind the raw egg in its membrane.

You will need:

  • Vinegar (= acid)
  • 1 raw egg
  • 1 glass

What to do:

  1. Place the raw egg carefully in the glass.
  2. Fill the glass with vinegar until the egg floats.
  3. Observe what happens on the egg shell. You should see effervescence.
  4. Leave your experiment for three days in a cool, safe place.
  5. After three days remove the egg from the vinegar and carefully dry it with kitchen roll paper.
  6. Take the egg in your hand and squeeze it gently. What does it feel like?

You can watch this experiment on YouTube:

Investigating Pressure with a Plastic Bottle – Experiment

Introduction

Air is made from gas particles. They constantly move around at a high speed. When speeding around like this, the particles often collide with the walls of their containers. For example, the air particles in a balloon move around and hit the balloon’s walls. These collisions cause the balloon to stay inflated. We call this gas pressure.

There are two ways to affect gas pressure. One is to change the number of air particles. When you blow up a party balloon, you add more air particles to it. More gas particles hit the walls more often and the balloon’s pressure increases.

The second method to increase pressure is by raising the temperature. When it is warmer, the gas particles have more energy and move faster. If the particles move faster, they hit with the walls more often and the pressure increases. When decreasing the temperature by cooling, the gas pressure will decrease.

In this experiment we are going to look at what happens to the pressure inside a plastic bottle when you cool down the temperature.

What you will need

  • 1 empty plastic bottle (a small bottle is enough, 500 ml or even smaller)
  • Freezer

What to do

  1. Remove the lid and put the empty plastic bottle in the sun or on the radiator to heat up a bit.
  2. Close the lid tightly, so nor more air can move in or out of the bottle.
  3. Put the bottle in the freezer and wait for one hour.
  4. Collect the bottle from the freezer. What has happened to it? Take notes.
  5. Now observe the bottle for a couple of minutes after taking it out of the freezer.

Questions

1. What happened to the bottle in the freezer?

2. Why did this happen? Look back at the introduction to find some clues.

3. What happened to the bottle after you took it out from the freezer?

4. Why did this happen? Look back at the introduction to find some clues.

5. Why was it important to close the lid tightly before putting the bottle into the freezer?

6. How could you improve this experiment?

Testing Acids and Alkalis in the Kitchen

Background

In this experiment you will investigate the properties of three substances in the kitchen to determine if they are acids or alkalis.

Acids have a sour taste. In high concentrations acids can burn your skin and other living tissue. But the acids you are working with in the kitchen have very low concentrations and safe to touch. Examples of laboratory acids are hydrochloric acid, sulphuric acid and nitric acid.

Alkalis have a bitter taste and feel slippery when you touch them. Alkalis in high concentrations can burn your skin or other living tissue too. But the alkalis in your kitchen have low concentrations and are safe to touch. One common alkali in laboratories is sodium hydroxide.

You will need:

  • 1 lemon or lemon juice
  • vinegar
  • dish washing soap (liquid soap for hand washing works too)

What to do:

  1. Copy the table below.
Substance Look Feel Taste Acid or alkali?
Lemon juice
Vinegar
Dish washing soap

 

  1. If you have a lemon instead of lemon juice you need to squeeze it now and collect some juice from it for your experiment.
  2. Look at the lemon juice, vinegar and dish washing soap and record in your table what they look like.
  3. In turns drop a bit of each of the substances on your hand and test what they feel like. Record it in your table.
  4. Now taste the lemon juice and the vinegar. Record what they taste like in your table. You do not have to taste the dish washing soap.

Questions

  1. Based on your data decide which substances are acids and which are alkalis and record it in your table. Use the text in the introduction to help you. It gives you information about the properties of acids and alkalis.
  2. What do you expect the dish washing soap would taste like? Why?
  3. Name two properties of acids.
  4. Name three properties of alkalis.
  5. Name two laboratory acids.
  6. Name one laboratory alkali.
  7. Which other acids and alkalis do you know that you have in the kitchen or the home?