Chalk, marble, shell. Fun chemistry experience at home

ENTERTAINING EXPERIENCES AT HOME
Directory / Entertaining experiences / Experiments in chemistry

Chalk, marble, shell. Chemical experiments

Entertaining experiments in chemistry

Entertaining experiences at home / Chemistry experiments for children

A piece of natural chalk CaCO₃ moisten with a drop of hydrochloric acid HCl (you can take pharmacy acid). Where the drop fell, a vigorous effervescence is noticeable. Put a piece of chalk with a "boiling" drop into the flame of a candle or dry alcohol. The flame will turn into a beautiful red color.

This phenomenon is well-known: calcium, which is part of the chalk, makes the flame red. But why acid? It, reacting with chalk, forms soluble calcium chloride CaCl₂, its splashes are carried away by gases and fall directly into the flame - this makes the experience more spectacular.

Unfortunately, such an experiment with pressed school chalk fails - it contains an admixture of soda (sodium salts), and the flame turns orange. The best experience is obtained with a piece of white marble moistened with the same acid. And you can make sure that sodium salts color the flame in an intense yellow color by adding a grain of NaCl salt to the flame (or just lightly "salting" the fire).

For the next experiment with chalk, you will need a candle. Mount it on a non-combustible stand and add a piece of chalk (marble, shells, eggshell) to the flame. The chalk is covered with soot, which means that the temperature of the flame is low. We are going to burn the chalk, and this requires a temperature of 700-800 ° C. How to be? It is necessary to increase the temperature by blowing air through the flame.

Remove the rubber cap from the pharmacy pipette and put on a rubber or plastic tube instead. Blow into the tube in such a way that air enters the flame just above the wick through the retracted end of the pipette. The tongue of flame will deviate to the side, its temperature will rise. Point the tongue at the sharpest part of the crayon. This area will become white hot, the chalk will turn into burnt (quicklime) lime CaO, and at the same time carbon dioxide will be released.

Do this operation several times with pieces of chalk, marble, eggshells. Place the burnt pieces in a clean tin. While they are cooling, place the largest piece in a saucer and drop water on the place that was heated. There will be a hiss, all the water will be absorbed, and the calcined area will crumble into powder. This powder is slaked lime Ca(OH)₂.

Add more water and drip a solution of phenolphthalein. The water in the saucer will turn red; this means that slaked lime forms an alkaline solution.

When the burned pieces have cooled, place them in a glass jar or bottle, fill with water, close the lid and shake - the water will become cloudy. You already know that we will now receive lime water. Let the liquid settle and pour the clear solution into a clean bottle. Pour some lime water into a test tube - and you can use it to experiment with gases as described earlier. Or tricks, like turning "water" into "milk" or "water" into "blood". A description of such tricks can be found in the section "Chemical tricks".

Author: Olgin O.M.

We recommend interesting experiments in physics:

▪ Water in an overturned glass

▪ sparrow on a branch

▪ Is white not white?

We recommend interesting experiments in chemistry:

▪ Chalk, marble, shell

▪ Color reaction of copper sulphate with ammonia solution

▪ Sweet miracles

See other articles Section Entertaining experiences at home.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Artificial leather for touch emulation 15.04.2024

In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>

Petgugu Global cat litter 15.04.2024

Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>

The attractiveness of caring men 14.04.2024

The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>

Random news from the Archive

Measuring Difficulty 27.12.2020

An algorithm for quantifying the complexity of structures has been developed. It is able to work not only with physical systems up to quantum ones, but also with images, video and even music.

An intuitive understanding of the complexity of systems and processes is inherent in any person. For example, one can easily distinguish the complexity of two drawings based on the dissimilarity of their elements to each other and the number of differing details. This is key information for the human brain to distinguish between objects of approximately the same size and shape. But how to digitize an idea of the complexity of an object and express it mathematically? After all, the need for a mathematical description that properly reflects the complexity of hierarchical non-random structures exists in many fields of science, from physics and geology to the social sciences.

An international team of scientists has developed a universal machine algorithm that can quantify, with a single number, the complexity of any two-dimensional or three-dimensional system. They successfully applied the method to accurately detect the phase transitions of magnetic materials by varying the complexity of the initial and final states. However, the algorithm is also capable of working with images, video, music, quantum systems, neural network algorithms for pattern recognition, and other systems. The authors argue that the proposed scheme is much simpler and cheaper than standard methods based on the calculation of correlation functions or using machine learning methods. They reported this in the journal of the US National Academy of Sciences (PNAS).

The method of calculating the complexity is based on the step-by-step division of the structure into blocks and the subsequent averaging of a certain characteristic within them. At each step, the algorithm compares the averaged ("fuzzy") structure with the original one and fixes the degree of change in the form of a numerical coefficient. For example, if the system analyzes an image, then the pixels in it are divided into blocks, in each of which they are averaged by color. Thus, if the image consists of many small details, then they will disappear, which will increase the difference between the "blurred" and the original structure. At the same time, the numerical coefficient expressing the complexity of the image also increases. The same operation is repeated with the "blurred" image. As a result, the algorithm calculates a numerical coefficient characterizing the degree of complexity of the image.

Other interesting news:

▪ Shark warning system

▪ Pectin is to blame for allergies

▪ Wet tropics emit more carbon than they absorb

▪ Bill Gates will create a supercow

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Measuring equipment. Article selection

▪ Article Conversation in favor of the poor. Popular expression

▪ article When did the yellow jersey appear in cycling? Detailed answer

▪ article Advertising agent. Job description

▪ article Automatic defrosting of the refrigerator. Encyclopedia of radio electronics and electrical engineering

▪ article Source for automotive electrical repair and battery charging. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews