A fun experience for kids with dry ice. Experiments with dry ice

In this article, we will look at some interesting properties dry ice, and also find out exactly how it interacts with water and some alkaline indicators.

First of all, let's get acquainted with the process of experiments in the video

During the experiments we will need:
- dry ice;
- phenolphthalein;
- thymolphthalein;
- sodium hydroxide;
- thymol blue;
- indigo carmine;
- flasks;
- measuring cylinder;
- ammonia solution.

The first indicators, that is, phenolphthalein and thymolphthalein, are colorless in a neutral medium. However, it is worth alkalizing them with sodium hydroxide, as the indicators change their colors.

Add dry ice to the solution. As a result, carbon dioxide begins to be produced, which reacts with a solution of sodium hydroxide. In this case, sodium carbonate or bicarbonate is formed, depending on the proportions. The acidity in the solution changes, as a result of which the indicators also change their colors.

The next indicators to be used during the experiment are thymol blue and indigo carmine. The first indicator in a neutral solution is yellow, and the second is blue.

We alkalize the solution. Thymol blue turns blue and indigo carmine turns green. Indigo carmine turns yellow in a strongly alkaline medium.

Let's try to achieve this.

We throw dry ice into the flasks. After a while, thymol blue turns yellow and then orange, and indigo carmine turns blue.

Finally, let's present the last experiment, during which a universal indicator will be used, which we fill in a graduated cylinder, add warm water, after which we add ammonia solution, after which the solution changes color to blue.

Add some more water.

And in the end we throw small pieces of dry ice into the cylinder.

Dry ice reacts with ammonium hydroxide, which is in solution, and gradually the solution changes color from purple to yellow.

The middle of winter is the time for experiments with ice. And even if the weather outside the window does not please with the presence of snow or frost, as it happens in some places, ice fun will add variety to your life and help you get into the winter mood, because the freezer of an ordinary refrigerator is enough to organize them.

Today we will not only freeze water and, but we will show the child how different substances affect ice, whether all liquids can be frozen, how cold affects various ones and, of course, we will not forget about creativity.

Let's start with those experiences that impressed my daughter the most.

Colored tunnels in the ice block

We will need a fairly large piece of ice (I froze a full bowl of water), as well as salt, a pipette and liquid paint (we used food colorings yellow, green and blue).

To make it easier to remove the frozen ice, pour hot water over the outside of the bowl. Now put the ice on a tray or in a large bowl. We give the child salt and ask him to salt the ice.

The most interesting begins - you will hear how the ice cracks and see small cracks appearing inside the ice block. After some time, the salt will begin to eat through larger passages along these faults.

For clarity, use paint - drip it onto the surface of the ice and it will penetrate into all the small cracks and tunnels. This experiment can be continued long enough until the salt has corroded the entire piece of ice. You will get an amazing spectacle and a lot of impressions. And besides, you will have time to talk about why salt corrodes ice.

Pay attention to the child that the ice began to melt as soon as you took it out of the freezer, because. the room is warm. When sprinkled with salt, the salt began to dissolve in the water on the surface of the ice and salt water turned out, which turns into ice only at very low temperatures. For example, a 10% salt solution freezes at -13 degrees. It was this saline solution that began to quickly melt the ice. And the cracks and cracks appeared due to the strong temperature difference between the ice and the salt solution.

Frost on the bottle

Continuing the conversation about the properties of a mixture of salt and ice, create frost in your kitchen with your child. To do this, in an opaque container, mix salt with snow or with crushed ice(we used pieces that were frozen on the inside walls of the freezer) and leave on a saucer with a little water.

After some time, a thick layer of frost will appear on the surface of the jar, and the water on the saucer will turn into ice. And all this in a warm room.

If you look inside the bottle, you will see that the snow has melted. At the same time, the temperature of the liquid is very low, less than 0. Because of this, water vapor from the ambient air settles on the outer surface of the bottle (condenses) and immediately freezes, turning into frost. The water in the saucer also freezes, forming an ice crust. This experiment clearly demonstrates how frost forms on trees when the temperature drops sharply at high humidity.

In addition, this property of salt and ice is used to quickly cool drinks before serving.

Rain in the bank

Ice will help us to demonstrate to the child the water cycle in nature. To do this, pour on the bottom 3 liter jar hot water, close it with a lid, and put a saucer with ice cubes on top. For clarity, you can glue the sun on the top of the jar.

Water heated in one way or another evaporates, turning into a gas, and rises up, forming a cloud of water vapor. There it cools and condenses, passing from a gaseous state to a liquid state (lift the saucer and see how many drops hang on the lid). When enough water is collected, it spills onto the ground in the form of rain, which we see from the flowing droplets.

Ice rink

Let's make an ice skating rink for toys? To do this, freeze the water on a tray or flat plate - this, as well as freeze the figure of a man in half a glass of water. Now we roll the figure like on a skating rink, at the same time explaining that the ice is slippery, due to the fact that it is quite smooth and at the same time covered with a thin film of water, which is why it is so easy to fall on it. If the ice is sprinkled with sand, then it becomes rough and it becomes more difficult to fall on it, however, as well as to ride.

hissing ice

Another experience that will delight your child. We freeze cubes of soda, water and dye in advance. I did this in advance, so my daughter did not suspect anything. When the cubes are frozen, put them on a plate, dilute vinegar with water 1: 1 and invite the child to pipette the solution onto colored ice. The ice starts to melt and hiss more and more.

Do you want to play with your child easily and with pleasure?

My daughter was delighted, but she could not understand what the secret was, because before that she had dripped the same pipette on ice and there was no hissing. I decided that the matter was in the water and began to drip onto the remaining large piece from the first experiment - there was no hissing. "Mom, confess, what's the trick?" - said my daughter and I admitted that there was soda in cubes))). Masha wanted to see this for herself and froze a few more pieces of soda, successfully repeating the experiment a few hours later.

The hissing is the result of a chemical reaction. acetic acid and soda to form carbonic acid, which is a very unstable compound and immediately decomposes into water and carbon dioxide, which we observe in the form of bubbles.

Ice melt time

We are actively mastering the time and decided to conduct an experiment with timing the melting of ice on a stopwatch. Figured out where the minutes, seconds and fractions of a second. We prepared two glasses with warm and cold water. At the same time they put the cubes in different glasses and waited.

In warm water, the ice melted after 2 minutes. 46 s., and in the cold - it melted for 40 minutes! Of course, even I did not expect such a turn of events. Tired of looking at the stopwatch, my daughter managed to eat and play. She called the experience "very difficult."

Freezing various liquids

For the experiment, we selected: water, sunflower oil, milk and 9% vinegar. They didn’t mark the time, but left it in the freezer overnight to see what would freeze and what would not.

The photo shows the liquid before and 12 hours after freezing.

As a result, only water and milk completely froze, sunflower oil became thick and cloudy. In vinegar, which at such a concentration should freeze at -3 degrees, only a few ice floes formed, complete freezing occurred only after 2 days. We concluded that the freezing point depends on the properties of the solution, and not every solution can be frozen in a home freezer.

Thread cuts the ice

To conduct the experiment, we need: a piece of ice, a thin thread and weights. As the last, we used wooden cubes, tying them to a thread. We place an ice cube on an inverted glass and put a thread on top, which is pulled down from both sides by two cubes.

The essence of the experiment is that in the place of increased pressure on the ice, the temperature of its melting changes. That. under the thread that presses, the ice should melt (as with the pressure of the skates on the ice). And the resulting water above the thread - to freeze due to low temperature environment(ice on both sides). It turns out that the thread, as it were, cuts the ice in half, leaving it untouched on top.

We carried out the experiment in the refrigerator so that the ice did not have time to melt quickly, but cutting the piece did not work. The thread froze a couple of millimeters and that's it. Neither an increase in pressure in the form of 4 wooden cubes, nor a change in temperature moved the experiment in the right direction. A piece of ice began to melt rapidly, and the experiment had to be stopped.

Drawing on ice

Let's move on to the more creative part. Try painting on the ice surface with paints. We used gouache. To rinse the brush, it is better to take cold water so that the drawing does not spread from the rapid melting of ice.

The name itself "dry ice" sounds a little strange, doesn't it? We are used to the fact that the ice quickly melts and turns into plain water… But here everything is much more complicated. Dry ice is actually a gas! Therefore, such ice does not melt, but sublimates, that is, it passes from a solid state immediately into a gaseous one! In this experiment, we will consider various physical and Chemical properties dry ice.

Reagents and equipment:

• dry ice;
• distilled water;
• liquid soap (dishwashing liquid);
• thymolphthalein;
• phenolphthalein;
• litmus;
• glass bowl;
• 3 beakers.

Step-by-step instruction

Take a piece of dry ice and put it on a metal spoon. After a few seconds, it will begin to bounce and rattle slightly.

Let's throw dry ice into a glass bowl with water - we observe white smoke and a rapid release of gas bubbles.

If you add a few drops to the water, a thick foam will appear from soap bubbles filled with white smoke.

Now let's take 3 beakers with indicator solutions: ( Blue colour), phenolphthalein (no color) and litmus (red-orange color). Next, add some sodium hydroxide. The solutions changed their color: indigo carmine turned green, phenolphthalein turned crimson, and litmus turned blue. Add a few pieces of dry ice to each glass. After some time, we observe a change in the color of the solutions to the original color.

Explanation of processes

Dry ice is a very simple substance (CO₂ solid phase). It is freely available and is mainly used for transportation food products or cleaning technical surfaces. But in the home laboratory, dry ice turns into an invaluable reagent! The “highlight” of dry ice is that it immediately passes from a solid state to a gaseous state without an intermediate liquid phase (this process is called ).

The sublimation temperature is -78.5°C. Upon contact with water, dry ice rapidly changes from a solid to a gaseous state. From the outside, it looks like boiling, only with a brighter and more characteristic vaporization. Moreover, the evaporating carbon dioxide is heavier than air (density 1.9768 kg / m³ versus 1.225 kg / m³), ​​and therefore “” does not rise, but spreads along the surface around the container with water.

When liquid soap is added, the bubbles of the released gas quickly foam it, and a thick foam is formed, filled with white carbon dioxide.

If you put dry ice in a metal spoon, it will bounce and rattle. The fact is that on a warm metal surface, dry ice sublimates very quickly, forming pockets of increased pressure, which is why our ice floe “jumps”.

When dry ice sublimes in water, the released carbon dioxide reacts with water, forming carbonic acid and changing the acidity. This property of dry ice can be used for beautiful color transformations with indicator solutions. In a neutral environment, indigo carmine is blue, litmus is red-orange, and phenolphthalein is colorless. When sodium hydroxide is added, the medium becomes alkaline, and the solutions change their color to green, blue, and crimson, respectively. When dry ice is added to alkaline solutions, carbonic acid is formed. As a result, the acidity of the solutions increases, the medium becomes neutral, and the color of the solutions changes to the original.

Precautionary measures

Be sure to wear gloves and avoid skin contact with dry ice, so as not to get a cold burn (dry ice temperature is -78.5 ° C).

Inhalation of CO₂ fumes can cause headaches.

Attention! Do not try to repeat this experience on your own.

The trick of dry ice is that it immediately passes from a solid state to a gaseous state without an intermediate liquid phase (this process is called sublimation). The sublimation temperature of carbon dioxide is -78.5°C. Dry ice is freely sold in two forms - briquettes and pellets. For experiments, it is more convenient to use granules, since they are small in size and easier to dose. On the other hand, dry ice is a consumable: up to 15% of its mass evaporates in a foam plastic container per day.

1. Pour warm water into one container, dishwashing detergent into the second (you can use liquid soap or liquid for soap bubbles).

The principle of experience

Most experiments with dry ice are based on the same principle. The fact is that upon contact with water, dry ice begins to rapidly change from a solid to a gaseous state, and it looks like boiling, only with a much brighter and more characteristic vaporization. Moreover, the evaporating carbon dioxide is heavier than air (density 1.9768 kg/m3 versus 1.225 kg/m3), and therefore the “smoke” spreads over the surface surrounding the container with water, and does not rise up.

2. Lubricate the edges of the container with water with soap. We take a rag tape (for example, cut from an old pillowcase) and immerse it in soap.

The experimenter pours water into a container and then throws ice into it. The warmer the water, the faster the ice will evaporate, the shorter and more visually effective the reaction. This is where the division into experimental areas arises. The first option is to allow the icy vapor to escape quietly and watch it spread.

3. We throw dry ice into the water - about half of the volume of water is enough. The more ice you use, the more steam will be generated.

The second option is to limit the vapor distribution area, that is, in other words, to evaporate ice in a closed space. If you do this, for example, in a closed plastic bottle, a cork will be knocked out of it (or even torn apart - never repeat this!), since in the gaseous state CO2 takes up much more space (gas density, we recall, is 1.9768 kg / m3, and the solid phase is 1560 kg / m3). But doing this with bottles is quite dangerous, much more interesting and easier to inflate with carbon dioxide. soap bubble.

4. With the help of a soap tape, carefully stretch the soap film over the container. Carbon dioxide will be locked inside, a huge soap bubble will begin to inflate (most often in combination with many small ones).

Precautionary measures:

With proper use, dry ice is completely safe, like regular water ice. But certain precautions must be observed:

1) Be sure to use gloves and never allow dry ice to come into contact with your skin for a long time. Its temperature is -78.5 C below zero, and you can get a cold burn. Simple cloth gloves are enough.

2) When transporting and storing ice, be sure to leave two or three small holes in the container with a diameter of a couple of millimeters. This will prevent the container from bursting. Never put ice in a sealed container.

3) Try to inhale the fumes as little as possible. CO2- this may cause a headache.

Get it done before the child grows up. Adventures, games, experiences Rizo Elena Alexandrovna

Secrets of dry ice

Secrets of dry ice

Not all adults have an idea about the possibilities of dry ice, so not only kids will like experiments with this unique substance.

So, dry ice is a solid form of carbon dioxide. It does not burn, does not smell of anything, but appearance resembles the usual "snow" ice. Dry ice is based on dietary carbon dioxide. Initially, it was created for use in industrial enterprises, but then it became available to everyone. Now anyone can buy dry ice in the store. It is sold in small packages and looks like white or transparent granules. What is so magical about this stuff? And why did I decide to open a new chapter of the book by experimenting with it? Judge for yourself.

Experience 1

YOU WILL NEED:

A container of water (any one will do - from a glass to a bucket);

Some dry ice.

This experience can be useful when creating stage effects of any scale. Throw a few grains of dry ice into a container of water (if the volume of the container is small) - and voila: you have a light haze in front of you, absolutely harmless to health! Want to make the fog thicker? No problem. Get a bucket of water and throw in more dry ice - the task is completed.

Since dry ice is used in Food Industry, it can be safely added to cocktails, cooling them, and at the same time giving the drink a mystical look.

Experience 2

YOU WILL NEED:

Soap bubbles or saturated soap solution;

Dry ice.

Pour soap bubbles or solution into a container and carefully add some dry ice. In the end, you will end up with nothing more than a bubble mist! There will be a feeling that the fog has made its way into each soap bubble, filling it to the limit. You will surely want to surprise all your friends with such a show.

Experience 3

YOU WILL NEED:

Thick soapy solution;

Thick paper towel;

Dry ice.

Pour soap solution into a volumetric mug (up to about half the capacity). Add literally a couple of dry ice pellets there and cover the mug tightly with a paper towel. Wait a few seconds until a thick soapy film forms, and then slowly remove the towel. The soap film will gradually turn into a huge bubble, striking in its size. Ultimately, of course, it will burst, and you will want to repeat the experience again.

This text is an introductory piece.