Supercooling a liquid involves cooling it below its freezing point without it becoming solid. Supercooling only works with liquids that do not contain any impurities, as this is the cause of crystallization. Once the liquid is supercooled, you can trigger its solidification which will then take place under your eyes. It sounds complicated, but be aware that you can supercool water in your own home with just a few simple steps.
Method 1 of 2: Use a bowl filled with ice and salt
Step 1. Gather the necessary materials
For this method, you will need salt, purified water, a small clean glass or plastic cup, a large bowl, and ice. If you have a thermometer, you can use it, but it is not essential.
- Your glass should be very clean. Impurities can cause the water to crystallize into ice before supercooling occurs.
- The bowl should be large enough to hold the glass and enough ice to submerge the glass.
Step 2. Fill 1/4 of the beaker with purified water
The amount of water does not have to be precise. Add enough water to be able to measure its temperature, but not too much, as you should be able to surround the goblet with ice above the water line. Place the cup in the center of the bowl.
Step 3. Fill the bowl with ice
Add enough ice so that the glass or tumbler is completely surrounded by it. There should be enough ice and the ice should exceed the water level in the cup.
- Be careful not to drop any ice into the cup filled with water.
- You can cover the cup before adding ice and salt to prevent accidental contamination.
Step 4. Sprinkle two tablespoons of salt over the ice
Adding salt to the ice will lower its melting point. If the melting point decreases, the temperature around the glass will drop.
- Again, be careful not to put salt in the glass or mug.
- You can place a clean thermometer if you have one.
Step 5. Wait about 15 minutes
Wait about 15 minutes or when the thermometer will indicate that the water temperature is below melting point. This reaction is faster than what happens in the freezer, so you will need to be extra careful. If you have a thermometer, you will be able to see exactly when the water will drop below the melting point.
- If you leave the water on for too long, it will freeze.
- If you do not have a thermometer, you can place a second bowl filled with tap water. When tap water freezes, your purified water should be supercooled.
Step 6. Initiate crystallization
There are two fun ways to freeze water. You can drop a piece of ice into the glass or tumbler, or you can pour the water over a piece of ice. After you drop the ice, the water should freeze quickly in the glass or mug. It is an instant gel. If you pour the water over ice, it will freeze over time.
Method 2 of 2: Using the freezer
Step 1. Find a bottle of purified or distilled water
You cannot use tap water because it contains minerals and other impurities that will cause ice to form during cooling. Purified water does not contain these impurities, which is why it is suitable for this experiment.
Water gains in volume when it freezes. So make sure the bottle is not completely full before you start
Step 2. Place the bottle in the freezer
Place the bottle in a corner where you can be sure no one will move it or hit it. If possible, tell friends and / or family not to use the freezer for the duration of the experiment.
If you live in a place where the outside temperature is below the melting point, you can place the bottle outside
Step 3. Leave the bottle motionless for 2-3 hours
The time it takes to supercool the water will vary depending on the temperature in your freezer. You can place a bottle of tap water in the freezer. Once it is frozen, your purified water must be supercooled and still in a liquid state.
- If you plan on 2 hours, check the condition of the tap water bottle every 15 minutes.
- When it is completely frozen, the pure water will be supercooled.
- If your purified water is also frozen, you either waited too long, moved the bottle during the process, or the water was not completely pure.
- Let it melt and try again for a shorter period of time.
Step 4. Remove the pure water from the freezer
Carefully remove the water from the freezer. When a liquid is supercooled, rapid movement may cause it to crystallize.
Step 5. Initiate crystallization
There are two fun ways to freeze water. You can shake the bottle and pour the water over a piece of ice. The water should freeze immediately after shaking the bottle. It is an instant gel. If you pour the water over ice, it will freeze as soon as it comes into contact with the ice. Keep pouring the water to watch it build up and freeze.
Supercooled water is always drinkable. You can make a granita with the rest of the melted ice
- Do not leave it on for too long!
- When water freezes, it grows in volume. Do not completely fill the bottle before putting it in the freezer.